CHAPTER 1
Introduction

The objective of this report is to provide guidance on properly depicting and using utility data for existing and proposed utilities in highway design plans. The guide entails the information collected and tools developed through NCHRP Project 15-81, “Guideline for Depicting Existing and Proposed Utility Facilities in Design Plans.” The research efforts of NCHRP 15-81 included the preparation of this guide. This project comprised a literature review, surveys, interviews with data users and practitioners, and the collection of depiction examples to identify best practices. These findings were then critically examined through peer exchanges and a validation workshop. This examination enabled the development of this guide to support a standardized approach for properly depicting and using utility data in highway design plans.

This research highlighted the need for standardized utility depiction in highway design plans because of vast inconsistencies in the accuracy and completeness of utility data, an unwillingness to deviate from existing policies and procedures (i.e., a mindset of “this is how we have always done it”), and a lack of education and/or knowledge as to the value and use of the utility data in the later stages of a projectʼs life cycle.

The guide provides practices for retrieving, depicting, and managing data for various utilities and for identifying and resolving utility conflicts. Additionally, they include tools deemed useful and appropriate, as collected and developed by the research conducted for this project. Also provided is an assessment of emerging technologies, including 3-D models, inclusive of utility data; robotic utility investigations (e.g., the FHWA-commissioned Robotic Utility Mapping and Installation System and similar ongoing research ongoing conducted by the project team); satellite imagery; artificial intelligence (AI); and machine learning for utility investigation.

The core objective of this report is to present beneficial practices for and approaches to accurately and comprehensively depicting utilities and managing utility data. To achieve this objective, the project team needed to establish a conceptual background and common understanding of associated terminology. The intended users of this guide include state department of transportation (DOT) engineers, consultants, utility owners, contractors, and other stakeholders who would benefit from clearly understanding and communicating utility-related information within highway project plan sets and project deliverables. This chapter provides definitions and a background on challenges of and approaches to utility depiction, examples of applications, specific considerations of One Call, relevant existing standards, the objectives and scope of the report, and the organization of the guide.

1.1 Background and Objectives

As more utilities are installed in their rights-of-way (ROWs) and unanticipated utility impacts adversely affect project schedules and costs, state DOTs are stressing the importance of utility coordination. Whether collected for use in highway design projects or as part of relocations or

permitted accommodations, utility data vary in source, detail, accuracy, and collection time frame, making it difficult to depict them correctly and reliably. 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, consultants, and utility owners to determine whether conflicts exist. Likewise, understanding where these conflicts exist is increasingly important as new initiatives, such as broadband infrastructure and electrification (i.e., electric vehicle charging infrastructure), are undertaken.

Efforts have been made to improve utility coordination since the 1980s, when the practice of what became known as Subsurface Utility Engineering (SUE) began. In these early years, SUE comprised concepts such as geophysics and point investigation to generate a better representation of underground utilities. By the 1990s, quality levels were introduced to enhance the information provided in highway design plans. Quality levels represent the degree of risk associated with the SUE information provided or describe the amount of information needed for design purposes. Over time, a variety of resources (e.g., the digitization of records, formalized standards) have been developed to help enhance the acquisition and management of subsurface utility data. By 2002, the ASCE published ASCE 38-02 Standard Guidelines for the Collection and Depiction of Existing Subsurface Utility Data. The same year, an update followed, with the title being adjusted to ASCE/Utility Engineering and Surveying Institute (UESI)/Construction Institute (CI) of ASCE 38-22 Standard Guideline for Investigating and Documenting Existing Utilities. The scope of this standard includes practices for utility investigation and documentation for aerial, surface, and subsurface utilities and continues the previous documentʼs impetus to establish the standard of practice for SUE. Also in 2022, ASCE published ASCE/UESI/CI 75-22 Standard Guideline for Recording and Exchanging Utility Infrastructure Data. The goal of this standard is to guide data collection, management, and exchange among stakeholders.

The previously mentioned resources have increased awareness of the utility information that must be obtained as part of SUE to effectively advance DOT projects regarding utility locations and potential conflicts. Support for the adoption of these practices has been recognized at the national level by the FHWA in the Strategic Highway Research Program and the Every Day Counts initiatives. This body of work has increased awareness of the information that must be obtained to effectively incorporate subsurface utility data into DOT projects. Additional funding support for the adoption of these practices has been provided to some DOTs through their application to the FHWA.

Varying levels of adoption and implementation of the previously mentioned resources across agencies have generated inconsistencies in ownership, comprehensiveness, reliability, accuracy, format, and attribute information, all of which have 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, it consists of an array of unstandardized records or drawings, often presented as a schematic view (sometimes in paper or image format), that cannot be imported or easily transcribed into a useful digital format. This information also typically fails 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 it is unknown whether the information from various sources (e.g., SUE providers, utility owners) is accurate, the existing data include contradictory information, no indication of data reliability exists, the information is missing or inappropriate, or the information is presented in inconsistent visualization and data formats. Additional confusion arises when utility investigations designated as SUE do not properly follow ASCE 38; the scopes of work for SUE services are inadequate; or firms, such as private-locate firms, are used with no accountability for their deliverables. Consequently, these

documents do not necessarily assist in reducing project risk or costs and can lead to unplanned project delays for DOTs (Meis et al. 2023). In addition, cost overruns and schedule delays, due to poor utility depiction and resulting unanticipated utility conflicts, are often unknown until the construction phase begins. The project ownerʼs ability to control costs and schedule is most challenging during the construction phase, and poor utility data and depiction practices almost always lead to the highway project being negatively affected.

In recent years, new technology, challenges to controlling cost and schedule overruns during the design and construction phases, and new ideas on ROW asset management have ultimately driven DOTs to seek better information about these facilities. Standardizing utility depiction, which includes investigation, documentation, evaluation, and communication, can reduce time and effort by ensuring the utility information is provided to data users and necessary entities in an acceptable and consistent format, with the appropriate level of comprehensiveness at the right time.

To address this challenge, the project team developed a set of guidelines that support intra- and interagency depiction of new and proposed utility facilities in highway design plans. In this report, the depiction of these facilities includes the investigation, documentation, evaluation, and communication required to meet the needs of the end user. End users for these data include utility coordinators and designers (for all types of design disciplines, including utilities, highways, structures, drainage, traffic, environmental, and so forth), construction project managers and contractors, and asset managers. These personnel can belong to either the utility owner or the state DOT (or their contractors, consultants, or vendors) managing the ROW. Facilities within the scope of these guidelines include both existing and proposed utility facilities (e.g., current infrastructure, relocations, new additions, and/or planned infrastructure). The intent of these guidelines is to support both 2-D and 3-D formats while recognizing that agencies have varying accessibility to and training on different software. The predominant focus of the guide is depiction in traditional plan sets because 3-D depiction within models is a developing and evolving area for future research.

The overarching objective of this research effort was to develop guidelines for transportation agencies on practices for depicting data from various sources to support design decisions, utility conflict identification and resolution, and depiction. These guidelines support end users in depicting existing, proposed, and relocated facilities; prioritizing the depiction of data from multiple sources; reconciling inconsistent utility data from various sources; and determining the reliability of depicted data for design standards. These guidelines were developed through a literature review, surveys, and interviews and validated in a workshop setting.

In addition, these guidelines are structured for public and private agencies to use, ensuring that utility information is provided to the necessary entity in an acceptable and consistent format, with the appropriate level of comprehensiveness at the right time. Because of the limited capacity of most agencies to continually capture a robust dataset, these guidelines further enhance the mechanisms for providing depicted information with varying levels of detail to meet the needs of end users.

1.2 Structure of the Guide

The following summaries are descriptions of each chapter in the guide:

Chapter 1: Introduction—This chapter provides definitions and a background of challenges of and approaches to utility depiction, examples of applications, specific considerations of One Call and existing standards, the objectives and scope of the study, and the organization of the guide.

Chapter 2: “The Vision”: The Ultimate Utility Depiction Deliverable—It is important for state DOTs to understand the opportunity to reduce project risk by adopting policies, standards,

and processes that take advantage of all available utility information. Having a complete picture of the existing and proposed utilities is essential to achieve any level of success. This chapter emphasizes that this understanding emerges only from an adequate and accurate depiction of all utility data during the project design stage, enabling intelligent, informed decisions pertaining to the purpose and need of the transportation project while accounting for how best to serve the public. The concept of optimal depiction is considered through the idea of a deliverable so complete that it does not require additional information, is kept up to date, and is clear and concise to any end user. The ideal approach would be to acquire these data before making design decisions, ensuring all the crucial information is understood, with utilities being recognized as one of the key elements.

Chapter 3: Utility Data for Depiction—Various data sources are available to identify the presence, location, and attributes of existing utility facilities. Often, each of these data sources provides unique insight into the characteristics of an existing utility facility, and when the data are collectively reviewed and properly evaluated, the accuracy and completeness of the resulting utility base map is significantly enhanced. Although the type and extent of the project may influence the data sources to be utilized, a combination of several of these sources typically provides the most accurate and complete utility base map. Integrating these various utility data sources into a utility base map yields one that is not only accurate and complete but also provides a solid basis for optimal decision-making throughout the design phase. This chapter presents data needs and provides effective practices and a conceptual plan in which all potential discrepancies and gaps in utility data are addressed, leading to better planning, design development, and project management.

Chapter 4: Utility Depiction—This chapter explores the complexities of and inconsistencies in how utility data are depicted in infrastructure projects. It emphasizes the importance of clear, adaptable, and stakeholder-focused visual representation, especially in the context of computer-aided design (CAD), geographic information system (GIS), and 2-D and 3-D modeling.

Chapter 5: Miscellaneous Topics—This chapter addresses a range of important yet often overlooked topics related to utility data management, including financial investment, coordination, project delivery, and gaps in current processes. It emphasizes the need for strategic planning, emerging technologies, and risk management.