Chapter 1 – Background

State Departments of Transportation (DOTs) are stressing the importance of utility coordination as more utilities continue to be installed within their rights-of-way (ROWs). Whether utility data is collected for use in highway design projects or as part of relocations or permitted accommodations, this utility data varies in source, detail, accuracy, and collection time frame, making it difficult to depict correctly and reliably. There is also difficulty in adequately communicating characteristics, such as accuracy, method of collection, etc., of this data to end users. The proper denotation, use, and standardization of utility data can substantially reduce risk in construction projects. However, without guidelines and specifications for the collection, management, and depiction of utility data, it can be challenging for state DOTs and utility owners to determine if conflicts exist.

The utility information needed and collected varies along a large assortment of variables. Utility information could be collected from records, surveys of markings from One Call public utility locate requests, private utility locating, or subsurface utility engineering (SUE) services, among other sources. While a true SUE study and report, according to the American Society of Civil Engineers (ASCE) 38 Standard, would document and provide details of accuracy and reliability and reconcile inconsistencies as seen in Figure 1, these studies are not consistently commissioned or implemented according to the standard.

At times, data collected through as-designed records (not as-built) and location data collected within a SUE investigation become depicted within highway design plans as though they are equivalently accurate, and major design decisions are often made based on the utility data provided. These decisions not only relate to utility conflict evaluations and the need for protection, avoidance, or relocation, but also can influence highway/roadway and structure

design decisions. Additionally, there is an array of forms in which a utility can exist, including existing, proposed, relocated, out-of-service (OOS), and abandoned. All too often, these differing forms of utilities are not clearly depicted within highway plans. These varying sources and forms lead to scenarios where data from various sources present contradictory information and concerns of reliability. Inconsistencies, such as those seen in Figure 2, become a challenge to reconcile if not handled appropriately.

Utility Conflict Management efforts and use of a Utility Conflict Matrix (UCM) are effective when utility information is collected and depicted precisely. Decision-making guided by a mindset to design to avoid or minimize impacts to utilities is extremely difficult without a clear depiction of existing utility information and without the confidence levels of that information. Designers facing uncertain information will generally default to requiring the utility to relocate. Therefore, it is important that DOTs understand the opportunity to reduce project risk by adapting policies, standards, and processes that take advantage of all available utility information.

Another issue that presents itself to utility coordinators is the coordination of varying utilities that provide location or relocation plans at differing states of accuracy, scale, or completeness, and which could potentially be in conflict with one another as well as with the highway project. There is a need for guidance to address these types of issues.

Efforts have been made to improve utility coordination since the 1980s, when the practice of what became known as SUE began. In these early years, SUE used concepts of geophysics and point investigation to produce a better representation of underground utilities. By the 1990s, Quality Levels (QLs) were introduced to enhance the information that was provided on plans. QLs are a representation of the degree of risk associated with the SUE information provided or a description of the amount of information needed for design. Over time, a variety of resources (e.g., One Call, the digitization of records, and formalized standards) have been developed to help enhance the acquisition and management of subsurface utility data. By 2002, the ASCE

produced ASCE 38-02, Standard Guidelines for the Collection and Depiction of Existing Subsurface Utility Data. In 2022, an update followed, adjusting the title to ASCE 38-22 Standard Guideline for Investigating and Documenting Existing Utilities. The scope of this standard includes utility investigation and documentation practices for aerial, surface, and subsurface utilities, and continues the previous document’s impetus to establish the standard of practice for SUE. In 2022, the ASCE 75 standard entitled, Standard Guideline for Recording and Exchanging Utility Infrastructure Data, was also published. The goal of this standard is to guide data collection, management, and exchange among stakeholders. These resources have increased the awareness of the utility information that must be obtained as part of SUE to effectively advance DOT projects in regard to utility locations. Support for the adoption of these practices has been recognized at the national level by the Federal Highway Administration, Strategic Highway Research Program, and the Every Day Counts initiative. This body of work has increased the awareness of information that must be acquired to effectively incorporate subsurface utility data into DOT projects. Additional support for the adoption of these practices has been provided at the national level by the Federal Highway Administration.

Varying levels of adoption and implementation of these resources across agencies have produced inconsistent ownership, comprehensiveness, reliability, accuracy, formats, and attribute information, which has amassed a new set of challenges for DOTs. For example, research has shown that DOTs believe utility owners should maintain records on “as-builts” (Meis et al., 2023). Yet, when DOTs receive information from utility owners, this information consists of an array of non-standardized records or drawings, often as a schematic view, sometimes as a paper or image format, that could not be imported or easily transcribed into useful digital form, and typically failed to represent or accurately depict utility facilities with proper reference to a published geodetic datum and established geographic coordinate system (Meis et al., 2023). Designers and utility coordinators bear much of the burden of reconciling this information with supplemental information. Complexity is added when the accuracy of information from various sources (e.g., SUE firms, utility owners, etc.) is unknown, present data includes contradictory information, there is no indication of data reliability, there is missing or inappropriate information, or information is presented in inconsistent visualization and data formats. Consequently, these documents do not necessarily assist in reducing project risk or project costs and can lead to unplanned project delays for DOTs (Meis et al., 2023). In addition, the cost overruns and schedule delays, as a result of poor utility depiction and resulting unanticipated utility conflicts, are often not known until the construction phase. The project owner’s ability to control costs and schedule is most challenging during this construction phase, and almost always leads to the worst-case scenario.

In recent years, new technology, challenges to control cost and schedule overruns during design and construction, and new ideas on asset management of the ROW, have ultimately driven DOTs to seek better information about these facilities. The standardization of subsurface utility depiction, inclusive of investigations, documentation, evaluation, and communication, can reduce time and effort by ensuring utility information is provided to the necessary entities, in an acceptable format, with the right comprehensiveness, and at the appropriate time.

To address this challenge, the NCHRP 15-81 research project was tasked to develop a set of guidelines that support intra- and interagency depiction of new and proposed utility facilities in highway design plans. The guide is inclusive of the investigation, documentation, evaluation, and communication required to meet the needs of the end user. End users for this data include (1)

utility coordinators and designers, (2) construction project managers and contractors, and (3) asset managers. These personnel can belong to either the utility agency or the state DOT (or their contractors, consultants, or vendors) managing the ROW. Facilities within the scope of the guidelines are then inclusive of both existing and proposed utility facilities (i.e., current infrastructure, relocations, new additions, and/or planned infrastructure).

The core objectives of NCHRP 15-81, a Guideline for Depicting Existing and Proposed Utility Facilities in Design Plans, were to:

• Identify current, successful practices for (a) retrieving, depicting, and managing data for various utilities; and (b) determining and depicting utility conflicts;

• Develop sound approaches to (a) depict existing, proposed, and relocated facilities; (b) prioritize the depiction of data from multiple sources; (c) reconcile inconsistent utility data from various sources; and (d) determine reliability of depicted data for design standards; and

• Develop guidelines for state departments of transportation (DOTs) on practices for retrieving, depicting, and managing data for various utilities and for utility conflict identification and depiction.

This research was needed to document a sound approach for collecting utility data, managing that data, and determining the reliability of data obtained from various sources. All of this data then needs to be communicated with designers, in plans adequate for other stakeholders, and eventually to construction staff and contractors. This approach could help prevent unnecessary utility relocations, reduce risks to the delivery of projects, and reduce project costs. This report presents the conduct of research report. The following chapters include the research approach, findings from the literature review, survey results, peer exchanges, and validation workshop, and a discussion of conclusions and suggested future efforts.