SUMMARY
Depicting Utility Facilities in Design Plans: A Guide

At first glance, the depiction of existing roadway features, such as pavement, shoulders, signage, and occasional utility structures (e.g., valve boxes, manhole covers, or utility poles), may appear straightforward. These visible elements are easily documented and modeled using conventional tools, such as surveys, photography, and computer-aided design (CAD). However, this surface-level simplicity belies the complexity hidden beneath.

Subsurface utilities, often buried from mere inches to tens of feet below the roadway and surrounding right-of-way (ROW), present significant challenges. These assets are invisible to the naked eye; therefore, their presence, attributes, condition, ownership, and potential impact on project cost and schedule cannot be determined through visual inspection alone. Because direct observation is either complicated or not possible under these circumstances, utility investigations rely on various techniques and communication among stakeholders to identify the location and characteristics of utilities. The depiction of utility data is the primary method of communication, and the goal of utility data collection and communication is to ensure accurate, timely, and cost-effective project delivery. However, utility data are rarely communicated consistently, and stakeholders often have differing expectations for how this information should be depicted. The reasons behind these inconsistencies have been explored in previous research; this study instead proposes practical solutions and guidance.

The proposed solutions integrate multiple disciplines, including utility records research, field investigations, coordination activities, highway planning and design, utility design and construction, and maintenance. Central to this approach is the development of standardized depiction methods (e.g., drawings, reports, models) that accommodate diverse stakeholder needs. Crucially, the research emphasizes the role of engineering judgment in managing uncertainty, acknowledging the risks associated with what cannot be seen or definitively known, and clearly communicating the known and unknown for the benefit of all stakeholders, particularly utility coordinators.

Project Context

Historically, departments of transportation (DOTs) have focused their limited resources on managing their own assets (e.g., bridges, culverts) within the ROW and have not collected sufficient information on utility infrastructure in these areas. For the purposes of this guide, utility infrastructure (herein referred to as utilities) includes, but is not limited to, above and underground facilities, supporting structures (e.g., guy-wires, anchorages, bridge hangers, supports, thrust blocks), and vaults. ROW crowding and incomplete information about these facilities create extra costs, schedule overruns, and safety issues during the design and construction phases of DOT projects.

In recent years, new technology and ideas in ROW asset management have prompted DOTs to seek better information about the facilities located there. To this end, resources have been developed to enhance the acquisition and management of these data (e.g., ASCE 38, One Call, digitization of records). The varying levels of adoption and implementation of these resources across agencies have generated inconsistent ownership, comprehensiveness, reliability, accuracy, formats, and attribute information, all of which have amassed a new set of challenges for DOTs. Simultaneously, data and visualization formats also vary across stakeholders, with challenges occurring when both insufficient and excessive information are provided. A further complication is the inconsistent mechanisms for communicating data, making it difficult for the intended user to make informed decisions.

Project Scope

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 the 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 coordinators and designers (for all types of design disciplines, including utilities, highways, structures, drainage, traffic, environmental, and so forth), construction project managers and contractors, asset managers, and utility owners and contractors. These personnel can belong to either the utility owner or the state DOT (or their contractors/vendors) managing the ROW. As a result, 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 objective of this research effort was to develop guidelines for transportation agencies on 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. They were developed through a literature review, surveys, and interviews with data users and practitioners.

These guidelines are structured for both public and private agencies to use, ensuring that utility information is provided to the necessary stakeholders in an acceptable and consistent format, with the appropriate level of comprehensiveness at the right time. Due to 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.

Project Outcomes

Guidance for depiction is provided for the following key challenges identified in this report:

• Type, ownership, size, shape, material, age, and condition of the utility
• Presence of encasements, accoutrements and appurtenances, and multiple cables or conduits indicated by a single line
• Confidence in and accuracy of the source information

• Depth data
• Size of vaults
• Limits of the utility investigation
• Communication of additional information in plans
• Status of facility (out of service, abandoned, inactive) and overhead (e.g., volts, sag, temperature, clearance requirements)

Overcoming these challenges, with consistency and clarity, will promote best practices and create a stepwise improvement related to interactions with DOT and utilities.