Strategies to Address Utility Issues During Highway Construction (2024)

CHAPTER 9. CONCLUSIONS AND RECOMMENDATIONS

CONCLUSIONS

While considerable progress has been made to address utility issues before a project goes to letting, a substantial knowledge gap still is how to manage utility conflicts during construction. NCHRP Project 15-69 addressed this issue by identifying causes of utility issues, evaluating the use of UIA tools, documenting case studies, developing functional requirements for a decision support tool, documenting procedures for conducting utility inspections, and documenting best practices and implementation recommendations. This report documents the research approach and activities completed, functional requirements for a DSS, and prioritized conclusions and implementation recommendations. Companion deliverables include guidelines to minimize utility issues during construction, presentation materials, and an implementation plan..

Causes of Utility Issues During Construction

The research team completed a literature review, conducted a practitioner survey, and analyzed a large sample of change orders and claims from across the country.

Literature Review

The literature review covered published materials going back almost 30 years. The review focused on practices and issues related to UR impacts on project delivery as well as construction and utility inspection practices.

Utility-Related Impacts on Project Delivery

Reports in the literature often relied on interviews with DOT officials, consultants, contractors, and, in some instances, utility owners. In most cases, results were aggregated across stakeholders, but some studies documented disaggregated results by stakeholder group. For example, in one study, the researchers noted that DOT officials, design consultants, and highway contractors considered utility relocation delays to be the top cause of project delays. However, while DOTs and design consultants identified DSCs related to utility conflicts as the second most frequent reason for delays, contractors identified errors in PS&E as the second most frequent cause of project delay. Interestingly, groups responded differently with respect to what they considered less frequent causes of project delays. For example, DOT officials and design consultants considered that owner-requested changes did not often cause project delays, but contractors thought otherwise. Design consultants considered that errors in PS&E did not often cause project delays, but DOT officials and contractors thought otherwise. Contractors considered insufficient work by them did not often cause project delays, but DOT officials and design consultants thought otherwise.

Some studies used change order and claim data to examine the impact of UR issues on project delays and cost overruns. For example, one study found that a little over 5 percent of change orders were related to utility conflicts. Another study reviewed utility cut damages and noted that utility facility damages caused contractor delays in 30 percent of projects. One of the reasons for UR delays was inaccurate or inexistent location data about utility facilities. Another study found

that causes of UR change orders included errors and omissions in PS&E, constructability issues, and DSCs. One more study found that UR delays accounted for 21 percent of all delays. A federal review found a lack of adequate data about existing utility facilities caused utility conflicts to be misidentified or not identified prior to construction, resulting, in turn, in contractors finding utility facilities during construction unexpectedly and causing project delays.

Reports in the literature pointed to a clear connection between UR issues and project delays. The connection was less clear between UR issues and project cost overruns. One of the reasons is that DOTs are more inclined to grant no-cost time extensions than granting change orders or approving claims that increase the total cost of construction. Most DOTs have strict policies about eligibility for reimbursement, which tends to limit the number of change orders or claims under this category. A related reason is that DOTs organize and group change orders a wide range of ways. How DOTs account for UR change orders varies widely, ranging from not having a separate category for UR reasons to disaggregated categories such as not relocating on time or unknown utility facilities affecting the project. Change orders that include multiple reasons into one document are also common, making it more difficult to isolate the effect of any one factor on project costs.

Other than participation in surveys and interviews, the technical literature was scant on the impact of UR issues to contractors. Examples noted included (a) lower production rates for installing underground appurtenances that were in conflict with existing or unknown utility facilities; (b) increased costs because of the need to work around existing utility facilities that had not been relocated; (c) crew delays while waiting on decisions regarding unknown utility facilities; and (d) having to schedule work during more expensive seasons, or push the overall construction schedule into the next construction season. This is one of the important reasons contractors consider information about utility issues in the bidding documents (e.g., level of detail about utility facilities on plans, notes, special provisions, or right-of-way status in relation to utility relocations) to be critical prior to deciding whether to bid or in evaluating the level of risk while developing estimates.

Construction and Utility Inspection Practices

The research team found 29 DOT websites that had specific requirements for construction or utility inspections. The requirements apply to a wide range of highway construction projects, utility relocations, and new utility installations within the right-of-way (typically via permit). The review reflects inspection requirements that are available in regulations and manuals, not necessarily whether actual inspections conform to those requirements.

It is common to require as-builts depicting the location of existing and relocated utility facilities within the right-of-way. In some cases, DOTs require as-built files to be tied to project control points or GNSS coordinates. It is common not to require utility owners to submit as-built files if there is not a significant deviation from plans, specifications, locations, and conditions. In some cases, utility owners must submit an affidavit or certification that there was not a significant deviation from the original plans. However, if the deviation from the original plans is substantial, the utility owner must submit as-built files showing actual locations, types, and sizes.

For utility relocations included in the highway contract, DOTs typically apply standard inspection and survey accuracy procedures. Some DOTs have specific data collection requirements for stormwater facilities (which DOTs typically own) and utility relocations included in the highway contract. However, it is unclear to what degree utility as-builts are prepared (or by whom).

Some DOTs have developed specific guidelines and requirements for preparing utility as-builts. In Colorado, CDOT has a program to collect utility location and attribute data using a web-based platform that includes three components: a data collection platform, data integration tools, and a web-based dashboard application. The data collection platform is a GNSS-based mobile software application that enables users to capture asset location and attribute data in the field, as well as upload the data to an online geospatial database in real time. The web-based dashboard application enables users to visualize and analyze utility and pipeline facilities based on information received from data collection devices via a real-time interface.

In Virginia, VDOT uses RFIDs to reduce the level of uncertainty with respect to newly installed utility facilities and, more specifically, as a damage prevention strategy. VDOT’s policy is to install RFID markers every 8 m (25 ft) along straight utility facility alignments; at significant horizontal and vertical changes in direction; at critical utility crossings, tees, and service connections; on specific facilities that are important to the utility owner; and on out-of-service facilities that are found or uncovered in the field. VDOT also generates as-built polylines showing utility alignments and prepares clickable PDF files that users can query. VDOT makes these files available to utility owners throughout the construction phase.

In Wisconsin, WisDOT require utility owners to submit X-Y-Z as-built coordinate data for all open cut or trenched utility work, as well as other situations in which a utility facility is exposed to facilitate a survey. Data collection requirements include collecting data every 50 feet and all angle points or direction changes along the utility facility centerline; surveying the top-center of each utility facility; and for multiple facilities (e.g., duct banks), measuring the total outside-to-outside width. WisDOT requires using boring logs if they can be used to produce X-Y-Z data.

Practitioner Survey

The research team conducted a national survey to identify risk factors affecting the utility process during the project delivery process, primarily during construction. The survey invitation went to multiple agencies and organizations, including AASHTO, APWA, ASCE, AGC, and ARTBA. A total of 194 responses included 192 responses from 44 states and two responses from Canada. Respondents included representatives of project owner agencies, consultants, contractors, and utility owners.

The survey instrument included a list of 61 risk factors that were grouped by project delivery phase. Respondents were asked to rate risk factors on a scale from 1 (least frequent) to 5 (most frequent) in terms of how frequently the risk factors contribute to project delivery delays, project cost increases, and utility relocation delays. Respondents could also type in additional risk factors (although the interface did not provide the option to rate these entries).

Based on the number of responses and individual ratings for each risk factor, the research team prepared tables showing average ratings. For visualization, table cells were color coded using a continuous gradation, with white used for the lowest value (i.e., 1.0), yellow used for the midpoint value (i.e., 3.0), and red used for the highest value (i.e., 5.0). Table 65 shows the top 20 UR risk factors that, according to respondents, contributed most often to project delays, cost overruns, and utility relocation delays.

Table 65. Top 20 UR Risk Factors by Stakeholder Group.

The research team also calculated standard deviations of the responses associated with each risk factor and corresponding rating. A scatterplot of average ratings versus standard deviations (Figure 15) revealed standard deviations were lower for either low or high average ratings than for mid-range average ratings, showing more agreement among respondents with respect to factors that were either low risk or high risk. Agreement among respondents was particularly strong for high-risk factors.

Change Order Analysis

The research team received change order and claim databases from nine state DOTs. Per NCHRP’s request, DOTs are shown by case numbers (not by name) to anonymize the discussion and results. The research team focused on six cases (1, 2, 5, 6, 8, and 9), which covered a wide range of change order record practices and styles. In total, the research team processed over 150,000 change order and claim records. The research team classified individual change order records as UR or NUR, but in some rare instances, records were classified as URS or NURS if the change order description was not sufficiently clear.

The research team prepared a dictionary of commonly used one-word and two-word UR terms. The dictionary of one-word UR terms included 60 entries. The dictionary of two-word UR terms included 148 entries. The research team also considered three-word UR terms, but the predictive power of these terms was low. To measure predictive power, the research team calculated the relative usage of each term as the number of UR change orders that mentioned a term divided by the total number of change orders that mentioned the term.

To classify change orders, the research team first used commonly used the UR terms and then reviewed the description and justification columns of each change order to assess whether the change order was UR, NUR, URS, or NURS. The research team also used AI models to detect trends and patterns that could show a change order was UR or NUR. After using the AI models, the research team reviewed individual records to confirm or, if necessary, change the label the AI tools predicted. The total number of UR change orders for the six cases was 11,803.

The research team classified UR change orders according to a list of nine disaggregated reasons. The research team prepared this list based on the results of the literature review and the practitioner survey. Reasons behind a substantial number of UR change orders were as follows:

• Errors and omissions in PS&E (33 percent).
• Inaccurate or incomplete data about existing or relocated utility facilities (23 percent).
• Changes initiated by project owner, contractor, or utility owner (12 percent).
• Delays getting utility owners to schedule utility relocations (11 percent).

Reasons behind a small number of UR change orders were as follows:

• DSCs (4 percent).
• Difficult or inadequate constructability of highway work or utility relocation (4 percent).
• Inaccurate or deficient utility relocation work (2 percent).
• Delays acquiring or clearing right-of-way or utility relocation sites (2 percent).
• Other (9 percent).

Except for utility relocation delays caused by utility owners, most reasons that cause a substantial number of UR change orders are reasons that a DOT can control, specifically, errors and omissions in PS&E (33 percent) and inaccurate or incomplete data about utility facilities (23 percent). These two reasons account for 56 percent of UR change orders. It is worth noting that the category of inaccurate or incomplete data about utility facilities includes data about abandoned facilities and obsolete utility location data that were not updated prior to letting.

Most reasons behind a substantial number of UR change orders are reasons that a DOT could address prior to letting, which highlights the importance of conducting utility investigations and identifying and resolving utility conflicts during the preliminary design and design phases. Pursuing these two strategies systematically could have a positive impact on 60–80 percent of UR change orders.

For DOTs where the change order description was sufficient, the number of UR change orders the research team classified as DSCs was low. For those states, the research team could figure out the actual reason behind the change order (even if the DOT had originally classified the change order as a DSC). This result is significant because it could point to many cases in which a change order might be classified as a DSC for convenience or because the official in charge did not have more meaningful categories to choose from, but the actual reason was completely different.

As mentioned, the research team used AI models to detect trends and patterns that could show a change order was UR or NUR. The research team used the change order database from Case 9, which included 104,540 records. For the AI simulation, the research team concatenated the description and remarks columns and used 102,302 records that had unique entries. Of this total, 95,290 (93 percent) were NUR records and 7012 (7 percent) were UR records.

After setting up the datasets for training, testing, and validation, the research team preprocessed the resulting text into a clean, standardized format. After preprocessing the data, the research team used three vectorization techniques to transform text into numerical data that could be used to train the AI models: CountVectorizer, TF-IDF, and BERT. The research team used the vectorized training datasets to train six AI models, as follows: Logistic regression, kNN, multilayer perceptron classifier, SVM, random forest, and deep learning.

The research team used accuracy, precision, recall, and F1 metrics to evaluate the performance of each model. The average classification accuracy of validation datasets for UR change orders ranged from 52–88 percent. Deep learning with the BERT vectorization technique achieved an overall accuracy or 88 percent for UR change orders, followed by random forest with the TF-IDF vectorization technique, which achieved 81 percent. Overall, the results point to the random forest model with TF-IDF vectorization as a promising choice for UR classification tasks, with slightly higher precision and recall and less computational demands than the deep learning model. Conversely, the deep learning model with the BERT vectorization had a higher accuracy and recall than other AI modeling strategies, making it suitable for scenarios where capturing most actual UR change orders is crucial.

The research team explored the feasibility of using the trained AI models from Case 9 to classify change orders from Cases 1, 2, 5, 6, and 8. UR accuracies for Cases 6 and 8 were higher than for

Case 9. Although surprising at first, a close analysis revealed that change order descriptions for Cases 6 and 8 were typically as detailed as those from Case 9, but they also had certain traits, such as using complete sentences and minimizing abbreviations and acronyms. These characteristics also made the manual review of the change orders easier. By comparison, UR accuracies for Cases 1, 2, and 5 were much lower than for Case 9. For Cases 1 and 2, change order descriptions were quite short. For Case 5, the change order database included short descriptions and long remarks, but the remarks column included mainly a list of modified items.

Utility Impact Analysis Tools

The primary goal of project risk management is to reduce the level of risk as the project evolves. Managing risk is not a one-time activity. As Figure 49 shows, reducing risk involves using five risk management steps at critical stages or milestones throughout the project delivery process.

Courtesy of the Texas A&M Transportation Institute

It is common to use risk registers to manage risk. A key component of a risk register is a color-coded matrix that combines the effect of probability of events and impact if the event happens. As a reference, FHWA developed a risk register spreadsheet tool that includes a spreadsheet to document the five risk management steps. The spreadsheet tool includes a risk register matrix and examples to help users conceptualize and classify risk probability levels. The tool includes a suggested list of risks, which includes only one UR risk: Unidentified utility impacts (under the construction functional area).

It is unclear to what degree DOTs use risk registers or the risk management steps described above to manage utility risks systematically. Nevertheless, tools that DOTs use to manage UR risks during project delivery include utility investigations, UIA, and UCM.

The technical literature is abundant on the techniques and methods to conduct utility investigations. As part of the literature review, the research team gathered DOT manuals and guidelines (typically utility or design manual) from the agencies’ websites. The review revealed that 38 state DOTs mention or describe procedures or requirements for utility investigations in their policy documents. Utility investigations based on the ASCE 38 standard (particularly QLB and QLA) are almost always conducted during the design phase. Increasingly, DOTs are beginning to conduct utility investigations earlier (i.e., during preliminary design). It is rare to use SUE during construction. Test pits are common during construction, primarily as a tool to confirm the location of underground features. Often, contractors begin digging test pits but end up digging slit trenches, particularly in situations where they cannot find underground features based on the information available to them on project plans. In complex urban environments, it is also common to complete mass excavations to expose underground utility installations over a wide area.

Some DOTs have developed tools to decide when to use SUE. In Pennsylvania, PennDOT uses a tool called UIA to choose the appropriate utility investigation quality level for a project. In general, UIA assumes that preliminary utility data are available prior to starting the analysis. UIA uses a two-step process. Step 1 is usually at the project level. Step 2 normally applies at the project segment or location levels because projects are not completely homogeneous regarding factors such as density or age of utility facilities.

In Georgia, GDOT has a UIA process, but this process is different from PennDOT’s UIA tool. GDOT’s UIA process relies on a utility conflict list to decide to what extent the project affects existing utility facilities. The analysis is typically recommended after gathering QLB data (around 30 percent design) and is used to assess where QLA test holes are necessary. GDOT recommends conducting a second UIA after the second submission of project files to utility owners to resolve any new or remaining utility conflicts (around 70–90 percent design if applicable).

In Washington State, WSDOT decides the type of utility investigation needed depending on the type of project activity as well as information that is found as the analysis progresses. WSDOT’s approach is that project teams should evaluate the costs of a higher quality level versus the potential costs associated with the risk of accepting a lower quality level.

In Colorado, the state legislature passed a law in 2018 that mandated the use of utility investigations in accordance with ASCE 38 (more specifically QLB and/or QLA) if a project has a construction contract with a public entity, the project involves primarily horizontal construction, and the project involves utility boring or has an anticipated excavation of more than 60 cm (2 ft) in depth and covers at least 93 m² (1,000 ft²). If the project meets these requirements, it then requires the services of a licensed professional engineer to conduct the utility investigation.

UCM is a comprehensive multi-stage process that involves the systematic identification and resolution of utility conflicts. Through interactions with practitioners all over the country, the research team has developed a generic, reference sequence of UCM activities throughout project delivery, which includes six concurrence points that correspond to important UCM stages.

As part of the SHRP2 Implementation Assistance Program, 18 state DOTs received grants from FHWA to conduct pilot implementations. The results of the FHWA pilot implementations were positive, including tangible economic and project delivery savings. UCM stages can vary depending on project characteristics. TxDOT has one of the most ambitious UCM programs in the country. As part of this program, TxDOT selected 25 pilot projects that were in the preliminary stages of project delivery (typically no more than 30 percent design). The pilot projects range from small two-lane rural projects to multi-lane urban freeway projects. As of this writing, half of the pilot projects had finalized design and moved to construction. This wide range of pilot projects has given members of the research team a unique opportunity to see firsthand a multiplicity of practices for managing utility conflicts. The research team has also documented lessons learned and provided recommendations to TxDOT officials (district and division level) and consultants to improve UCM practices.

Case Studies

The research team completed three case studies to highlight exemplary practices on how to manage utility issues, particularly during the construction phase. The three case studies included a bridge reconstruction and new pedestrian bridge construction project in Colorado, a highway widening project in Texas, and a local improvement project in Virginia that involved roadway construction and complete replacement of utility installations.

Colorado Project

The Grand Avenue Bridge Replacement project in Colorado involved replacing and realigning the existing bridge on SH 82 over a railroad track, the Colorado River, and I 70 in Glenwood Springs. A new pedestrian bridge was designed to carry the existing utility facilities that were attached to the old vehicular bridge. The utility relocation design involved converging all existing lines into a vault, and then elbowing up to the underside of the pedestrian bridge.

To reduce the risk of delays during construction, it became clear that the existing utility facilities that were attached to the existing vehicular bridge would need to be relocated during the first phase of the project. To facilitate the utility coordination process, CDOT implemented a utility engineering-based program that included early utility investigations during project deliveries, early identification and resolution of conflicts, and frequent coordination with utility owners. Based on the positive results that CDOT experienced with this project, CDOT decided to extend the program to other parts of the state.

The project had few UR issues during construction. The project had a construction management consulting contract that included utility inspections. The project included the preparation of utility as-builts. CDOT registered 39 change orders for this project. None of the change orders had a utility delay reason code. One change order was classified as a DSC, but the description field showed “Pedestrian Bridge F-07-BA Utilities.”

Texas Project

The US 281 project involves widening 8 km (5 mi) on US 281 in San Antonio, Texas, from a four-lane median-divided cross section to a six-lane freeway with two-lane directional frontage roads. This project, Segment 2 of a larger highway expansion project that includes two segments,

is currently nearing completion. Segment 1, which is 4.8 km (3 mi) miles long, was recently completed.

The district designed Segment 2 in 3D. Most aspects of the design were in 3D, but the traffic control plan, phasing, and utility coordination were not. All utility files were in 2D. Although the project was designed in 3D, the bidding package was prepared using 11×17-inch sheets. TxDOT included Segment 2 in the pilot UCM implementation described earlier. This implementation included the preliminary design and detailed design phases. Segment 2 also has a CEI contract that includes utility coordination and utility inspection services. Most utility owners took care of their own relocations, whether reimbursable or not. Some utility relocations were included in the highway contract.

District utility staff conducted QLB and QLA utility investigations in preparation for the 30 percent design plans. The district used a standard UCM template and showed the location of all utility conflicts on working project files. The district documented and resolved 316 utility conflicts. Most utility conflicts were resolved via relocation, but in a few cases, the district found changes to the highway design to avoid existing utility facilities, resulting in an estimated $4.6 million in economic savings and 24 months in project delivery time. The district also tried to complete utility relocations before letting. For Segment 2, the district used a right-of-way clearing contract to accelerate utility relocations prior to letting. This type of contract was relatively new at the department at the time the district used it for Segment 2. Given the positive results, TxDOT has since expanded it to other districts.

For utility relocations that could not be completed prior to letting, the district staged the relocations to minimize impacts to the construction schedule. The district did not integrate utility relocation schedules into the contract schedule but did prepare an Excel file showing the planned relocations for all utility facilities. In addition, the district prepared a CMP to manage utility relocations during construction. CMPs have been required at TxDOT since 2016 in situations where a district estimates that complying with certifications and permit clearances is likely to extend beyond 3 months after letting.

For non-joint-bid relocations, the CEI consultant highlighted the need for extra coordination with utility owners because the contractor wanted to work on several fronts simultaneously (as opposed to south-north, as originally envisioned during the design phase). The consultant also highlighted the need for utility owners to be flexible during construction. In addition, it was critical to develop effective working relationships with utility contractors.

For joint-bid relocations, the construction manager found the RFI process to be too slow (for effective utility coordination purposes) and found it be more expedited to coordinate with the utility contractor directly to anticipate issues. Weekly meetings with utility owners on the job site helped them stay on top of things. Most joint-bid relocation issues were related to constructability of water main relocations. Lessons learned from managing these issues resulted in recommendations to strengthen utility investigation deliverables, including conducting test holes to confirm tie-in locations during the design phase instead of passing the risk of not knowing these locations to the highway contractor.

A review of change orders revealed that the percentage of UR change orders and their associated dollar amount was considerably lower for Segment 2 than for Segment 1. Overall, the change order numbers show that the UCM implementation, adding utility coordination and inspection to the scope of the CEI contracts (which included utility location verification), and other strategies (such as using a right-of-way clearing contract) had a positive impact on the management of utility issues both prior to letting and during construction.

Virginia Project

The Rethink 9 project in Hillsboro, Virginia, was a 0.8 km (0.5-mi) project that consisted of two roundabouts (one roundabout on either end of the project), raised crosswalks, sidewalks, a new municipal drinking water system, wastewater treatment facility, stormwater collection system, undergrounding all overhead utility lines, and dark-sky-compliant streetlamps. The project was first proposed as a congestion mitigation project. However, the town’s utility infrastructure was deemed to be unsafe or inadequate and in need of replacement. Addressing all traffic and infrastructure components simultaneously resulted in a significant reduction in the duration of impacts to traffic, residents, and businesses during construction.

One third of the project cost went to utility and stormwater infrastructure. The project included strategies to build utility systems in a narrow roadway, utility coordination for relocation work, and close coordination for consecutive and concurrent relocation work. It also included preparation of utility as-builts using RFID devices. VDOT normally relocates utility facilities prior to letting. In this project, utility facilities were relocated during construction to reduce impacts. The contractor used the same MOT for utility construction and roadway construction. In practice, construction staging involved a significant amount of coordination between the contractor and each utility owner involved.

The only UR change orders were related to the amount of concrete in the duct banks. At several locations, the contractor excavated more than what was necessary or removed large boulders that resulted in more concrete being poured than what designers had estimated.

Functional Requirements for a Decision Support System

The research team prepared a list of requirements for the development of an IDSS, which, as requested by NCHRP, will focus on the classification of UR change orders and identification of their causes. The requirements include (a) recommendations to improve the clarity, completeness, and conciseness of change order descriptions as new change orders are generated and (b) IDSS components and mockup interface components that illustrate potential workflows. Both sets of requirements are based on observations the research team made analyzing change orders from Cases 1, 2, 5, 6, 8, and 9.

The recommendations to improve the clarity, completeness, and conciseness of change orders as new change orders are generated could be included as part of a Help subsystem in the IDSS, as a separate guide document, or as part of an existing construction management software the DOT already uses. Specific recommendations are as follows:

• Implement a quality control process to minimize typing errors.
• Avoid using acronyms or abbreviations whenever possible.
• Cite the contract and change order number when referring to other change orders instead of repeating the description of those change orders.
• Avoid including information about the project scope or information that other columns in the change order already capture.
• Include the utility type in the description.
• Standardize utility owner names.
• Include sufficient information to characterize the utility conflict properly.
• Specify the cause of the change order when a new facility is discovered.
• Explain the reason that caused a DSC.
• Standardize the structure of the description column.

For the IDSS components, the research team assumed the IDSS would be installed on a cloud server and that user access to the system would be via a web browser. The cloud server could be owned by the DOT or hosted on a commercial platform. Components include an API to extract change order data from an existing PMS; IDSS components to process and analyze data, generate reports, and manage the system; and a user interface to interact with and run the IDSS.

The IDSS will likely have the following user interface pages: Home, Data Processing, Reports, and Management. The user interface includes a Help subsystem, which could be a standalone page or a tool that is integrated into the other pages. The research team anticipates the IDSS will have the following functions: Data Import, Data Classification, Post-Processing, Dashboard and Reports, Notifications, and System Management.

Procedures for Conducting Utility Inspections

The research team developed utility inspection procedures considering data collection equipment, software, and protocols. As part of this task, the research team conducted field tests to assess the positional accuracy of low-cost data collection equipment. The focus was inspection activities that involve verification of locations, dimensions, areas, and volumes, not other related utility inspection activities such as verification of materials or the completion of inspection diaries.

Data Collection Equipment and Software

The research team conducted a review of data collection equipment that was suitable for conducting utility inspections. The focus was low-cost devices that could still provide cm-level positional accuracy levels. The research team reviewed UASs, smartphones and tablets, and external GNSS antennas. Most UAS applications used for inspections involve the use of small rotary platforms. RTK support is desirable but not essential if GCPs are used in the field. Of interest here is UASs that are NDAA compliant, such as the Parrot Anafi USA and Skydio X2D Color. In both cases, the UAS has a built-in camera and does not support exchangeable payloads. The camera pitch ranges from –90° to +90°, enabling the collection of imagery looking up. The maximum flight time is a little over 30 minutes. The Skydio X2D has omnidirectional obstacle avoidance capabilities, which is helpful for inspecting aboveground installations such as poles,

towers, and cables. The Parrot Anafi USA does not have substantial obstacle avoidance capabilities.

Recent smartphones and tablets have the capability to receive data from multiple GNSS constellations, such as GPS, GLONASS, Galileo, BeiDou, QZSS, NavIC. A wide range of mobile devices are suitable for conducting utility inspections. The research team conducted tests with two smartphones (Samsung Galaxy S22 and Apple iPhone 14 Pro Max) and two tablets (Samsung Tab Active3 and Apple iPad Pro 11).

The research team also reviewed external GNSS antennas. Of interest here are devices and companion services that offer cm-level positional accuracy at lower costs than traditional GNSS equipment. A typical business model is one in which the cost of the GNSS antenna is low (say $500–$5,000). The receiver provides a positional accuracy between 60 cm (2 ft) and 1.5 m (5 ft) in autonomous mode, but when connected to an RTK correction subscription service, the positional accuracy improves up to 1–3 cm horizontally. RTK subscription rates range from $4,000 per year to $400 per month or $100 per day. Depending on the brand and model, GNSS receivers can connect to public RTK networks for free, but in other cases, users must pay an unlocking or access fee to the GNSS vendor, after which it is possible to connect to the public RTK network. The research team tested the following external GNSS antennas: Bad Elf Flex, Leica Zeno FLX100 Plus, Trimble DA2, and viDoc RTK Rover. The research team also examined whether these GNSS antennas could connect to a number of RTK networks.

The research team conducted a review of several data collection apps for mobile devices. Of interest were apps that enable users to complete activities such as, but not limited to uploading a data dictionary to the device and collecting data using preestablished feature classes and drop-down lists; associating pictures and videos with specific features; comparing planned versus as-built locations; gathering unstructured point, line, and polygon data; collecting picture sets needed for SfM photogrammetry and the production of 3D models; collecting LiDAR data needed to produce 3D models; and adding comments. The research team reviewed the following apps: Trimble Penmap, Leica Zeno Mobile, ArcGIS Field Maps, ProStart PointMan, PIX4Dcatch, and Bentley iTwin Capture Mobile.

The research team conducted benchmark tests to assess the positional accuracy of the various external GNSS antennas described above. For the tests, the research team used an NGS first-order Class II vertical control point. The horizontal positional accuracy of GNSS antennas on autonomous mode (i.e., without the support of RTK) varied from 1–2 m (3–7 ft). The vertical error for all antennas on autonomous mode varied from 0.2–9 m. This result is not surprising and confirms what has been known for many years about vertical errors from GNSS antennas being consistently worse than horizontal errors.

When using RTK, the horizontal positional accuracy varied from 1–4 cm. When using RTK, the vertical positional accuracy varied from 1–10 cm. As in the case of the autonomous mode data, values were more erratic compared to the horizontal positional accuracy. These results show that low-cost GNSS antennas connected to an RTK network can provide cm-level positional accuracies, which are sufficient for most utility inspection activities. The review confirmed the availability of several apps for mobile devices, which have stakeout functions that enable users to compare design locations versus actual locations on the ground.

The research team did not conduct benchmark tests for the UASs, but a previously completed research involved a comprehensive assessment of the positional accuracy of commonly used UASs under a variety of scenarios, including autonomous mode, with and without GCPs, and with and without RTK. On autonomous mode, the UASs had a horizontal positional accuracy of 4–9 m. Whether using RTK or GCPs, all UAS-SfM solutions produced accuracy levels that compared favorably to RTN checkpoint location coordinates.

Data Collection Protocols

The research team identified five basic data collection use cases that apply to a wide range of utility inspection activities that involve verification of locations, dimensions, areas, and volumes, as follows:

• Use Case 1: Project Survey Control Point Verification. In this use case, the inspector occupies one or more project SCPs to make sure the coordinate system parameters used for the data collection are consistent with those used for project survey control. This use case also provides an opportunity to verify the positional accuracy of the GNSS antenna by using the SCP coordinates the project surveyor has provided.
• Use Case 2: Point Features. This use case involves having a georeferenced digital representation of the plans on the mobile device and using the stakeout tool of the data collection app to find the point feature and verify whether its location is within a pre-specified tolerance.
• Use Case 3: Line Features. This use case involves having a georeferenced digital representation of the plans on the mobile device and using the line stakeout tool of the data collection app to find the line feature and verify whether its location is within a pre-specified tolerance.
• Use Case 4: Polygon Features. This use case involves having a georeferenced digital representation of the plans on the mobile device and using the stakeout tool of the data collection app to find the corners of the polygon feature and verify whether its location is within a pre-specified tolerance.
• Use Case 5: 3D Objects. This use case involves using a device such as a UAS or a smartphone to capture multiple images around the area of interest and processing the images using photogrammetry software. It may be possible to augment this capability by using LiDAR to generate point clouds and fuse the data with the results from the photogrammetric process. The result is a georeferenced 3D model of the feature of interest (and, by extension, the area surrounding the utility feature) that meets project datum requirements.

RECOMMENDATIONS

Based on the identification of causes of utility issues during construction, review of the use of UIA tools, documentation of the three case studies, development of the functional requirements for a decision support tool, and development of procedures for conducting utility inspections, the research team has several recommendations to improve business practices at DOTs.

Realizing that a substantial number of utility issues during construction trace their origin to events or decisions that take place during preliminary design or final design, the research team

organized recommendations into two major categories: Recommendations prior to letting and recommendations during construction.

Recommendations Prior to Letting

Conduct Utility Investigations Systematically

ASCE 38 outlines typical activities for conducting utility investigations and describes four quality level attributes for individual utility features: QLD, QLC, QLB, QLA. ASCE 38 includes examples showing utility facilities and their quality levels on utility investigation deliverables. ASCE 75 describes essential elements for recording and exchanging data about the location and other attributes of underground and aboveground utility infrastructure. Although this guideline focuses on newly installed, repaired, or otherwise exposed or accessible utility infrastructure, the structure and content of ASCE 75 makes it suitable for preparing and submitting utility investigation deliverables.

A recommended practice is to conduct utility investigations as early as possible during project delivery, with each quality level contributing to a reduction in the level of uncertainty about utility facility locations depending on project needs. General guidelines are as follows:

• Preliminary design (prior or up to 30 percent design): Conduct preliminary utility investigation based on existing records (QLD), conduct utility investigation using geophysical techniques (QLB), and conduct utility investigation based on aboveground utility facilities (QLC). In general, it is advisable to first gather QLD data for the entire project, and then schedule the collection of QLB and QLC data. Because of the cost of QLB data, it is best to use geophysical techniques wherever there is a need for reliability in the horizontal location of utility facilities. Often, this requirement makes it necessary to use QLB for the entire project, but in other cases, it is possible to limit the collection of QLB to strategic areas.
• Detailed design (30–60 percent design): Conduct utility investigation using test holes (QLA). Because of the cost of test holes, it is best to strategize test hole locations using criteria such as outcomes of earlier utility investigation activities and the identification of locations where knowing the elevation of an underground utility facility is essential (e.g., gas or high-pressure pipeline crossings, structure foundations, and culvert inlets and outlets).

A related recommended practice is to use the five risk management steps at critical stages as part of the UIA process (Figure 49) to assess what kind of utility investigations are needed at each stage.

One of the goals of conducting utility investigations is to find and document abandoned lines. According to 49 CFR 192, an abandoned facility is a facility that is permanently removed from service. State utility accommodation policies typically define an abandoned facility as a facility that is no longer operational, and the owner does not intend to use it in the future. Although ownership remains in place, a frequent problem is that utility owners remove abandoned facilities from their inventories. QLD utility investigations often miss abandoned facilities. One of the benefits of using geophysical techniques (QLB) is that it becomes possible to find existing

utility facilities (including abandoned facilities) that were not captured by using only existing records. If a project only relies on QLD investigations and perhaps a few test holes during the design phase, the risk of finding abandoned facilities during construction is high.

Utility investigations should include all existing aerial and underground infrastructure (including tenants or co-located utility facilities on poles and in conduits) that might have an impact on the highway project, not just facilities that are normally considered utilities. Specifically, utility investigation scopes should include existing infrastructure the DOT owns (e.g., stormwater lines and ITS electric and communication infrastructure). Utility investigations often exclude this infrastructure, but the result is inefficiencies that the DOT must correct later.

Apply A UCM Approach to Identify and Resolve Utility Conflicts

UCM is a comprehensive multi-stage process that involves the systematic identification and resolution of utility conflicts. UCM stages can vary depending on project characteristics. As a reference, Figure 5 shows a generic depiction of the project delivery process assuming a design-bid-build project delivery method. Figure 5 shows six concurrence points that correspond to important UCM stages.

A recommended practice for UCM is to depict the location of utility conflicts on a utility layout and use a utility conflict list (also called a utility conflict matrix) to document each conflict, the process to analyze resolution alternatives, and the alternative that was finally selected. Specific recommendations to apply UCM effectively are as follows:

• Involve all stakeholders in the UCM process. UCM is a team effort that involves all stakeholders, not just the utility coordinator. The level of involvement depends on the role of each actor.
• Document each conflict using the utility layout, utility conflict list, and companion documentation (e.g., project files, pictures, specifications, schedules, right-of-way acquisition plans, and drainage design files).
• Identify and analyze conflicts in preparation for the completion of milestone deliverables. This UCM approach is proactive, turning the utility layout and utility conflict list into living documents, as opposed to first preparing milestone deliverables (e.g., at 30-percent design, 60-percent design, 90-percent design, or 100-percent design) and then conducting the utility conflict analysis.
• Use content from the UCM process to prepare the utility statement that is necessary to prepare the construction bid package, showing utility work completed prior to construction, utilities not in conflict with the project, and utility work that must be completed during construction.

A recommended practice is to schedule reviews of the utility conflict layout and list by subject matter experts in areas such as, but not limited to, geometric design, structures, retaining walls, soundwalls, right-of-way acquisition, environmental impacts and remediation, drainage, construction management, traffic operations, lighting, and ITS. To avoid the risk of delays, a recommended practice is to schedule these reviewing keeping in mind when different activities normally take place. For example, requesting a review by traffic signal specialists around 60 percent design would be advisable because signal design is often one of the last activities during

design (60–90 design), and pole foundations can be 1.2–1.8 m (4–6 ft) deep. Similarly, it is common to finish the drainage design around 60 percent design, but preliminary drainage design happens much earlier. It is at that time when it would be strategic for the hydraulic engineer to conduct a utility conflict review. In practice, the hydraulic engineer should remain involved in the UCM process until the hydraulic design is completely finalized.

Conduct Constructability Reviews Whenever Utility Facilities Are Involved

It is common to conduct constructability reviews in situations where highway design features affect existing utility facilities (provided a proper utility investigation reveals the location and impact associated with these facilities). Constructability reviews of utility relocations are much less common. Having a construction engineer review utility conflicts and utility relocation plans helps with the identification of issues that utility relocations might face in the field as well as issues the highway contractor might find during construction. Effective constructability reviews often involve utility owners.

A real-world example is the case of a bridge project that included the use of a large crane to install the bridge beams. The constructability review concluded that the weight of the crane and the drill shaft construction might affect an existing 20-cm (8-in) gas line crossing. To mitigate the impact, the contractor had to load and transport the crane around the gas line crossing. It was also necessary to evaluate the construction of the drill shafts to minimize the risk of vibration on the gas line.

A common situation that requires a constructability review is when a proposed storm sewer is located below existing utility crossings. The constructability review helps with the identification of protect-in place measures for the affected utility facilities. Another situation where a constructability review is critical is when there is a risk of an electric shock. For example, when cranes are installing guardrail, signals, or lighting structures, a constructability review helps to decide whether to de-energize an electric line or what kind of protection might be necessary.

A constructability review can assist with the selection of strategies for managing existing utility facilities that contain hazardous materials. It is often necessary to remove these facilities, but sometimes the best decision is to isolate and protect the affected area. A constructability review can also help with the determination of how to manage abandoned utility facilities. Utility owners are normally responsible for removing utility facilities that are permanently out-of-service. However, removing these facilities requires mobilization of crews and equipment as well as excavation and other disruptions within the right-of-way. In the context of highway construction, it might be in the best interest of the project to assign the task of removing abandoned facilities to the highway contractor.

In many cases, a utility facility might not appear to be in conflict with the final highway design, but a constructability review helps to uncover the conflict and decide on the most appropriate course of action. A common occurrence is roadway subbase preparation or rough grading taking place near an underground utility line crossing. The constructability review might show, for instance, whether to protect the utility line in place or to have a utility owner representative onsite while construction is taking place. Another common occurrence is traffic phasing and temporary detours. A constructability review might reveal that a utility facility is in conflict with

a traffic phase or a temporary detour even though the utility facility is not in conflict with the final highway plans.

Include Utility Relocations in Assessment of Critical Path for The Project

Often, utility relocation schedules only consist of a highly aggregated list of tasks and durations, missing important information to put utility relocation activities in proper context with respect to the highway construction project. Effective utility relocation schedules are those that are organized into manageable, logical phases, and include activities, durations, and milestones. Commonly used project management software should be used to prepare Gantt chart schedules that include these elements and enable the identification of schedule dependencies and critical paths. Ensuring that utility relocation schedules are as accurate as possible is important because, ultimately, if a utility owner does not clear its utilities on time in an area where the highway contractor needs to work, the DOT can be liable for delay costs.

Utility relocation schedules should also include related right-of-way acquisition schedules, particularly when a utility relocation involves existing easements or depends on the acquisition of right-of-way parcels. Combining these schedules for each utility owner enables utility and right-of-way stakeholders to understand the requirements and constraints by each discipline. For utility relocations, examples of essential elements to include in the relocation schedules are fabrication times, acquisition of replacement easements, duration times for fiber splicing (which can be months or years), and service disruption moratoriums. Including these elements in the utility relocation schedules becomes even more important if the utilities are not cleared by the time the construction project goes to letting.

Including the time and sequence of right-of-way parcel acquisitions is also important. Right-of-way acquisitions happening too close to the letting date increases the risk for right-of-way acquisitions and utility relocations to be part of the critical path, often making it necessary to complete these activities during the highway construction phase.

Prepare Robust Utility Relocation Documentation

Required supporting documents to prepare utility agreements are the utility relocation plans, the utility relocation schedule, and the utility relocation cost estimate. Consolidated plans and schedules for all utility relocations are also required for inclusion in the construction bid package.

The checklist in Table 66 includes both required elements and enhancement elements for inclusion in utility agreements and the construction bid package. Required elements are those that must be included in a required document or deliverable. Enhancement elements increase the completeness and quality of documents or deliverables that already include the required elements. The research team recommends including the checklist in Table 66 in the list of deliverables for designers and consultants, with a clear indication of which elements must be included in the final deliverables.

Table 66. Required Elements and Elements that Enhance the Quality of Utility Information.

Develop a Utility Construction Plan and Include It in The Highway Contract

A UCP assembles elements from the utility relocation plans and utility relocation schedules into one document to create a narrative that explains how the highway construction can be affected and specific steps to manage those impacts. UCPs focus primarily on utility relocations that are not included in the highway contract under the assumption that the construction bid package already includes all the necessary information for in-contract utility relocations.

Utility coordinators should begin developing UCPs well in advance of the letting date when it is clear which utility relocations will not be cleared prior to letting. Specific recommendation for preparing UCPs are as follows:

• Each project is different. A rule of thumb is to begin developing the UCP at least 6 months prior to the letting date.
• Prepare utility relocation schedules (see recommendation above), making sure that schedules are organized into manageable, logical phases, and include activities, durations, and milestones. Commonly used project management software should be used to prepare Gantt chart schedules that include these elements and enable the identification of schedule dependencies and critical paths. Make sure that utility relocation schedules are as accurate as possible because, ultimately, if a utility owner does not clear its utilities on time in an area where the highway contractor needs to work, the DOT can be liable for delay costs.
• Identify which utility relocations are anticipated to finish prior to letting, between letting and a pre-specified deadline, and after the pre-specified deadline. The pre-specified deadline depends on the project and how quickly the highway contractor will start construction. A rule of thumb is 3 months after the letting date, although many contracts allow contractors to start within 30–45 days.
• Update utility relocation schedules and revise the utility relocation completion schedule often. This activity, which starts during design, should continue during construction until all utility relocations are complete. The schedule must be monitored and enforced to avoid unnecessary delays and claims.

• Include in the UCP all utility relocations that will not be in the highway contract and that will not be completed prior to the pre-specified deadline. Part of the analysis involves deciding which utility relocations to include in the highway contract as a strategy to manage risks during construction. Municipality-owned utility infrastructure, such as water and sanitary sewer, as well as communication duct banks and related civil infrastructure are often suitable candidates for inclusion in the highway contract.
• Include in the UCPs information such as advance notice(s) to the utility owner, required work by others (interim and finish), access restrictions for highway contractor, coordination with other utility owners and stakeholders, and assumed duration for work by other stakeholders. This information helps with the identification of areas where it is necessary to restrict highway construction because of active utility relocation activities.
• Include the UCP in the construction bid package, making sure to add a disclaimer that the information is provided to assist prospective bidders in planning their work, but that the selected contractor is not liable for activities and schedules that only utility owners can control. Alternatively, the DOT might decide not to include the UCP in the bid package. A downside to this strategy is that UCPs might not be shared with prospective bidders at all, rendering UCPs useless. Even if the DOT then shares the UCP with the contractor, the contractor might discount its benefits (and therefore ignore the utility relocation schedules included in the UCP) because the UCP was not a contract document.
• Use a contract-level special provision to outline an escalation process for utility clearance dates, which includes required coordination with utility owners and how to manage situations that might trigger delay change orders or claims.

Use Right-of-Way Clearing Contracts for Utility Relocations

A standard item in highway construction specifications deals with the removal and disposition of all obstructions to prepare the right-of-way for construction. It is common to include in the item a provision for protecting features on the right-of-way and pruning trees and shrubs as directed. Item measurement and pay is usually by the area cleared, length cleared (regardless of right-of-way width), or tree removed.

When utility relocations take place before letting, a question that often surfaces is who should pay for clearing the area of the right-of-way that is necessary for the relocations. A common complaint from utility owners is that the DOT should be financially liable because right-of-way clearing is included in the highway contract anyway. If utility owners pay for clearing the right-of-way, the risk of overcharging increases. This effect multiplies if multiple utility relocations are taking place, each one requiring right-of-way clearing. Other risks include having to complete separate environmental reviews if the environmental clearance for the highway project does not include partial right-of-way clearing activities.

Right-of-way clearing contracts outside the highway contract are useful for clearing the right-of-way in preparation for utility relocations, particularly in heavily vegetated areas. In a typical situation, only one right-of-way clearing contract is necessary to prepare the area for all utility relocations, therefore reducing the risk of overpaying for multiple right-of-way clearing activities. Another benefit is to increase the chances each utility owner will relocate correctly and on schedule. In addition, it may be possible to use right-of-way clearing contracts to remove abandoned lines when the owner cannot be located or is out of business.

Recommendations During Construction

Stake Right-of-Way and Maintain Markers for Utility Relocations

When a utility owner places facilities on a project without knowing with certainty where the right-of-way line is, the risk exists that utility crews will guess at the right-of-way line and place the utility facility in the wrong location or, worse, on private property. Having to relocate utility facilities a second time to correct the error can affect the sequence of highway construction. Staking the right-of-way before utility relocations start would help to prevent this issue from occurring. Requiring the utility owner to hire a surveyor to find or set the right-of-way is an obvious solution. However, the DOT runs the risk the survey might cost more than what the utility owner had anticipated because the surveyor is not familiar with the project or takes longer to research the necessary project data and boundary evidence.

Staking the right-of-way is particularly critical on roadways where the DOT did not acquire right-of-way for the project, and many monuments have been knocked out over the years as a result of roadside maintenance operations, fence construction, and utility installations close to the right-of-way line. However, staking the right-of-way on proposed right-of-way is also beneficial, particularly if the new corners have not been set or contractors knocked them out placing new fences. In addition, utility crews often do not have metal locators to find property corners, or it is not obvious where to search for the corners, and utility owners often do not have professional surveyors on staff.

Staking proposed roadway structures or other proposed utility installations is also critical to avoid the risk of secondary utility relocations, particularly when planning the installation of utility relocations that are too close to those features. Having a survey crew stake the proposed structures, poles, or lines enables utility owners to verify they are locating their facilities correctly and far enough away to avoid a new conflict.

Develop A Common Repository of Utility Data and Other Project-Related Data

One of the most time-consuming tasks during construction is to keep all stakeholders on the same project datum and checking for field locations not matching utility plans or project files. Using an incorrect datum, scale factor, or benchmarks is a common issue that requires multiple meetings to resolve the differences and then having to revise the plans. An effective strategy to address these issues is to set up a cloud-based shared drive to store up-to-date information that all stakeholders can access. Having a common set of benchmarks and associated metadata and making this information available ensures that all stakeholders use the same datum for all field measurements, including utility relocations and productions of utility as-builts. The shared drive can also store a list of all contacts including utility owners, contractor personnel, inspectors, and emergency numbers, as well as copies of project files and as-built utility plans as they become available.

In the absence of common benchmarks and metadata, utility owners may be convinced they are using correct data and are relocating correctly but are actually causing new conflicts. The result is confusion and delays when the contractor finds these problems. A similar problem occurs when utility crews do not use the approved locations but instead decide on the fly where to place

the relocated facility. Utility crews often do not have survey support and might not appreciate the importance of placing facilities at the approved locations.

Schedule Utility Preconstruction Meeting or Include Utility Owners in Highway Preconstruction Meetings

Preconstruction meetings are standard highway construction events. These meetings set the stage for the establishment of communication protocols and other procedures among stakeholders, including contractor, subcontractors, DOT construction manager, design consultants, surveyor, inspectors, and others. It is not common to include utility owners or representatives in these meetings. One of the reasons is that the meeting agenda may already be full and adding utility topics would significantly extend the meeting time. Another reason is the number of utility owners that need to be invited could easily exceed the meeting capacity. Nevertheless, for small projects or projects that do not have complex utility relocation issues, including utility owners in the highway preconstruction meeting is certainly advisable. For large highway construction projects, or in situations that involve complex utility issues to address during construction, it is best to schedule a separate utility preconstruction meeting.

UR topics to discuss during the utility preconstruction meeting include, but are not limited to the following:

• Points of contact and communication protocols.
• Confirmation of utility relocation plans and schedules.
• Utility outage restrictions (often driven by time periods when utility service cannot be interrupted) that might affect construction activities, as well as requirements and protocols for reestablishing utility service to customers.
• Concerns about the contractor working near utility facilities and protective measures that will be required.
• External impacts to utility relocation schedules (e.g., limited crew availability or crews that need to be diverted due to outside forces).
• Traffic control in construction zones.
• Access issues for utility stakeholders and adjacent landowners.

Schedule Recurrent Utility Coordination Meetings During Construction

Utility owners that are relocating facilities during highway construction should have frequent meetings with the highway contractor and other DOT representatives (e.g., construction manager, inspector, and surveyor). A recommended practice to set up recurrent meetings at the job site office (e.g., weekly). As needed, meetings could also take place at specific locations on the project to assess field conditions. Examples of items to discuss include relocation status and schedules, coordination and cooperation needs, traffic control, environmental compliance, BABA requirements, and when materials will be on site for inspection.

These meetings offer the contractor the opportunity to notify utility owners when utility personnel will be needed on site to avoid damage to a utility facility or to mitigate a safety concern (e.g., by discussing where staking is needed or where it is necessary to locate existing or proposed utility facilities). Advance staking of proposed utility infrastructure by the utility owner

may be required by the highway contractor when exact locations of both utility and highway structures are critical. Coordination between the contractor and utility owners is particularly critical near areas such as high-pressure gas lines or electric transmission lines.

Use Plastic Pipe to Mark Underground Lines

One of the challenges when installing new underground utility facilities or when exposing existing lines is once the excavation is backfilled, it is quite difficult to remember where the facility was located. Even when accurate X-Y-Z data are collected, construction crews do not necessarily have ready access to the data. Placing a 5-cm (2-in) plastic pipe vertically on top of the line when the trench or test hole is still open and allowing the pipe to protrude slightly above the ground level enables all stakeholders to easily locate the underground facility. The contractor, utility owner representatives, or a surveyor can also use a tape to verify the depth of the line relative to any work that may be happening on the surface. This low-cost technique is particularly effective in situations where it is not clear whether all stakeholders using the same datum.

Use Utility Layout to Show Abandoned Utility Facilities

If a contractor finds a utility facility that was not included in the utility plans or listed in the utility conflict matrix, it is impossible to know without more information whether the line is active, inactive, out of service (temporarily or permanently), or abandoned. To minimize its liability, the contractor stops working in the area until a positive confirmation arrives about the status of the line. A strategy to manage abandoned utility facilities during construction is to prepare plan sheets that show all abandoned lines that are found within the project limits, along with information about the owner and the agreed upon disposition of the line (e.g., removal or cut and fill with grout). Keeping the inventory of abandoned lines up-to-date also helps with reducing the risk of delay claims.

Conduct Utility Relocation Inspections Systematically

Requirements for the inspection of utility construction vary with the complexity and location of the utility work and the associated impacts on the transportation facility. For smaller installations, it may be sufficient to spot check for general conditions of the relocation, traffic control, and safety. In other cases, the complexity of the utility work may require continuous and close observations of (a) construction methods, including excavation, installation, backfilling, and restoration, and (b) alignment and dimensions (i.e., X-Y-Z coordinates) of the utility facilities within the right-of-way.

In addition to verifying actual locations, an important focus of the inspection job is to verify the utility facilities as installed are not in conflict with adjacent facilities and structures. Even if a facility is installed properly according to the plans, checking for conflicts in the field helps to uncover hidden situations the contractor or other utility owners might have missed otherwise, but which need to address, sometimes as soon as possible, to avoid the risk of project delays.

Utility inspection procedures should be like those used for roadway inspection with respect to record keeping, diaries, pictures, videos, and other supporting data. An obvious difference is that utility inspections are also used to gather data for utility agreement reimbursement purposes or

for verification of utility installations that are authorized via permit. A critical implementation issue is which stakeholder(s) should conduct utility inspections. Regardless of whether utility relocations are reimbursable or not reimbursable and whether utility relocations are included in the highway contract or handled by utility owners directly, both DOT and utility owners should have an interest in the utility inspection tasks and their outcome. A common belief at DOTs is that utility relocations should be the sole responsibility of utility owners, but utility owners also often believe that DOTs cause utility relocations with their projects and therefore should be fully responsible for them. A more effective approach is to discuss the issue of utility inspections openly during utility coordination meetings and outline clear responsibilities and expected outcomes by each party. Often, the only practical approach is to absorb the cost of conducting utility inspections within the project budget, either by using internal inspectors or by using CEI contractors.

The research team tested low-cost UASs, smartphones and tablets, and external GNSS antennas that are suitable for conducting utility inspections. The results show that low-cost data collection equipment connected to an RTK network can result in cm-level positional accuracies, which are more than adequate for conducing utility inspections. The review confirmed the availability of several apps for mobile devices, which have stakeout functions that enable users to compare design locations versus actual locations on the ground. The data collection equipment can be used in a variety of ways, including but not limited to the following:

• Project survey control point verification: The inspector occupies one or more project SCPs to make sure the coordinate system parameters used for the data collection are consistent with those used for project survey control.
• Point feature: The inspector uses the stakeout tool of the data collection app to find the point feature and verify whether its location is within a pre-specified tolerance.
• Line feature: The inspector uses the line stakeout tool of the data collection app to find the line feature and verify whether its location is within a pre-specified tolerance.
• Polygon features: The inspector uses the stakeout tool of the data collection app to find each of the corners of the polygon feature and verify whether its location is within a pre-specified tolerance.
• 3D objects: The inspector uses a UAS or a smartphone to capture multiple images around the area of interest. Some devices also have LiDAR data collection capabilities. After processing the data using photogrammetry software, the result is a georeferenced 3D model of the feature and area of interest.

Improve The Quality of Change Order Documentation to Facilitate Future Analyses

Extracting data about UR change orders and claims from the DOT’s data repository is essential for understanding how UR reasons can cause issues during construction.

Recommendations to improve the clarity, completeness, and conciseness of new UR change orders and claims are as follows:

• Implement a quality control process to minimize typing errors.
• Avoid using acronyms or abbreviations whenever possible.

• Cite the contract and change order number when referring to other change orders instead of repeating the description of those change orders.
• Avoid including information about the project scope or otherwise information that other columns in the change order already capture.
• Include the utility type in the description.
• Standardize utility owner names.
• Include sufficient information to characterize the utility conflict properly.
• Specify the cause of the change order when a new facility is discovered.
• Explain the reason that caused a DSC issue.
• Standardize the structure of the description column.

If a DOT uses change order reason codes, a recommendation for UR change orders is to use the disaggregated reasons listed in Table 44. If the DOT does not use reason codes or it is not possible to change the list of reason codes, a recommendation is to include the appropriate reason from Table 44 as part of the change order description.

A recommended practice to facilitate the extraction of UR change orders and claims from an existing database is to implement a cloud-based DSS that interacts with the database and includes components that enable the classification of records, various analyses, and preparation of reports. The IDSS could be owned by the DOT or hosted on a commercial platform. Figure 35 shows the main system components, including an API to extract change order data from an existing PMS; IDSS components to process and analyze data, generate reports, and manage the system; and a user interface to interact with and run the IDSS.

Processing and analyzing change order data in the IDSS would involve a combination of automated record classification and manual review and editing. The research showed the feasibility of using AI models to automate the detection of UR change order records. Overall, the results point to the random forest model with TF-IDF vectorization as a promising choice for UR classification tasks, with slightly higher precision and recall and less computational demands than the deep learning model. Conversely, the deep learning model with the BERT vectorization had a higher accuracy and recall than other AI modeling strategies, making it suitable for scenarios where capturing most actual UR change orders is crucial.

The research also showed the feasibility of using trained AI models using data from one DOT to classify change order records from other DOTs. The tests showed that if the change order description structure is similar to that used for training AI models, using AI models to classify change order records from other DOTs is feasible. The feasibility of using AI models to extract UR change order records from other DOTs decreased if change order descriptions were too short or used too many acronyms. It would be necessary to train AI models specifically for these cases.

SUGGESTED RESEARCH

Effective classification of change orders to facilitate future analyses.

DOTs organize and group change orders in many different ways. Typical categories include contract administration, errors and omissions in PS&E, DSCs, change in scope, right-of-way, and utilities. The level of disaggregation in change order classifications varies widely. NCHRP 15-69 focused on UR change orders. Based on a review of more than 150,000 change orders from six state DOTs, the

research uncovered multiple instances of false positives (i.e., change orders the DOT had incorrectly labeled as UR) and false negatives (i.e., change orders the DOT had not identified as UR or missed a UR classification). False positives and false negatives are missed opportunities that produce errors in the analysis of what causes UR change orders. In at least one DOT, the number of change orders that turned out to be UR was almost three times the number of change orders the DOT had originally classified as UR.

To assist with the change order analysis, the research team successfully used AI models to detect UR change orders. Research extending the use of AI models to all other reasons that cause change orders and claims, coupled with a judicious manual review of a significant sample of change order records, would help DOTs in developing a much more accurate understanding of what is causing change orders. The research would also produce an updated classification of change order reason codes and recommendations to improve change order descriptions.

BIM architecture for utility facilities.

DOTs are quickly adopting BIM to develop and deliver highway projects. FHWA is also heavily promoting BIM for infrastructure as a collaborative work method for structuring, managing, and using data and information throughout the lifecycle of assets within the right-of-way. Unfortunately, managing the utility process in this environment (from utility investigations to UCM, utility design, and utility construction) is conspicuously absent in most BIM applications that DOTs are pursuing.

As a result, while DOTs are actively pursuing BIM strategies for highway design and construction, utility facilities are still managed using ineffective approaches. For example, data exchange for utility investigations still relies on GIS technology that has not been updated for three decades, which does not allow for complete, standards-based 3D representations of utility facilities. In many cases, utility investigations produce highly detailed data and visualizations of utility facilities, but this level of detail and visualization is completely lost during data exchange, reducing the DOT’s capability to effectively identify utility conflicts and manage the resolution of those conflicts in a 3D environment. A similar problem occurs when preparing as-builts after completing the installation work in the field.

Research is needed to develop and test a BIM architecture for utility facilities in ways that facilitate (a) data exchange during all phases of project delivery without losing data integrity and completeness and (b) integration with all other aspects of BIM-based project delivery activities, from design to construction and post-construction. Developing and testing the BIM architecture for utility facilities that complies with existing and emerging data exchange industry standards would produce a more complete BIM architecture for the overall project delivery process.