American Association of State Highway and Transportation Officials

Special Committee on Research and Innovation

FY2023 NCHRP PROBLEM STATEMENT TEMPLATE

Problem Number: 2023-D-10

Problem Title

Risk-Based Subsurface Utility Engineering Needs Assessment

AASHTO Committee on Right-of-Way, Utilities & Outdoor Advertising Control: Subcommittee on Utilities

AKD60, TRB Standing Committee on Utilities

Background Information and Need For Research

Subsurface utility engineering is the convergence of new site characterization and data processing technologies that allows for the cost-effective collection, depiction, and management of existing utility information. These technologies encompass surface geophysics, surveying techniques, mapping techniques, CADD/GIS systems, etc. Rather than disclaiming responsibility for existing utility information, subsurface utility engineers certify utility information in accordance with a standard classification scheme (utility quality levels) that allows for a clearer allocation of risk between the project owner, project engineer, utility owner, and constructor. State Transportation Agencies (STA) often must design in proximity of existing underground utility facilities that are not a party to the design contract. Designers may receive utility data of various sources and unknown accuracy to make decisions about utility conflicts. Due to the variability, the data may be highly accurate or less accurate and missing the actual utility location by inches, feet, or tens of feet. As a result, project success requires a sound understanding of the risk introduced by the locational accuracy and confidence of the existing utility data. The risk lies with designers use of utility information of varying degrees and quality to make critical design decisions. This effort involves assumptions regarding the location, quality of the record-based plans and unknown or estimated distances between existing and proposed facilities. The high risk nature of using inaccurate utility data or inaccurate assumptions about the data has resulted in unnecessary design work, unnecessary requests for Subsurface Utility Engineering (SUE) data, unnecessary relocation of third-party facilities, and re-design or safety risks during-construction.

ASCE standard 38/02 describes quality levels (QLs) of SUE data that are a value judgement as to the locational uncertainty of existing facilities. In general, QL D is more uncertain than QL C, which is more uncertain than QL B and finally QL A. Utility quality level D (QLD) information is determined primarily from existing records. Although each level provides increasingly better certainty about the location of a utility facility, only QL A provides location information in x, y, and z direction with typical surveying accuracy. However, this information is only available at certain points within a project, which are called test holes.

Figure 1. Cross Section of Utility Facility Within Conflict Envelope

Literature Search Summary

STAs are increasingly using 3D project design and modeling techniques during highway design, for example Building Information Modeling (BIM) tools or 3D CAD tools. Designing in three dimensions allows automated clash detection using a conflict envelope around existing and planned facilities. This conflict envelope (or “zone of influence”) is defined by the expected variability of the depicted underground facility, which is information that is not readily available to designers (Figure 1). This research is intended to help define the conflict envelope for a variety of utility facility types.

• ASCE 38/02

• Kevin Vine. Subsurface Utility Engineering (SUE): Avoiding 4 Potential Pitfalls to Ensure a Successful Program. Paper Prepared for the Presentation at the Utilities Management - Past Present Future Session Of the 2014 Conference Transportation Association of Canada (TAC) Montréal, Québec.

• Michigan Utility Coordination Committee’s Geospatial Utility Infrastructure Data Exchange 2014 Pilot.

• Michigan Department of Transportation Road Design Manual.

Research Objective

This research will aid designers in answering the question “How close can I design to an existing facility?” As such, the research will assess utility records versus test hole data or SUE QLA data to determine statistical accuracy for risk-based SUE need determination, which will greatly aid project practitioners. The research will generate statistics for use by designers and project managers to make risk-based decisions regarding the need for SUE on STA projects, and to be input into a BIM model for use in clash detection.

This research will also identify and prioritize other risk factors to be used to automate risk-levels. Some of these key attributes may include items such as facility-owner, facility-type, age, facility dimensions, facility material, installation method, existing record quality, etc. The research will also develop a SUE risk matrix guidance document to recommend when and how to implement SUE on a project. The research will address the following objectives:

• Develop guidance for STAs to determine when to involve a SUE consultant after the STA has collected utility information originating from various sources.

• Perform a statistical analysis of record project utility location data versus actual locations to define conditional risk-based envelope matrices that are dependent upon known project conditions (to be identified during the research.)

• Determine whether it is feasible to develop an algorithm that can predict the need for SUE that varies as a function of the deviation from the “3D Point (QLD)” based on results of the statistical analysis of actual location (QLA) vs records (QLD).

• Develop a risk matrix for obtaining the proper SUE Quality Levels within areas of a project.

• Develop a Scope of Work SUE checklist.

Urgency and Potential Benefits

Contractors working on STA project around the country employ multiple mechanisms to protect themselves from poor utility data provided within construction plans. All states now have a one-call statute in place whereby the contractor must call all known utility owners before construction begins. Utility owners then have the burden of marking their utilities on the ground surface for damage prevention purposes. Many times, the paint marks indicating the location of the utilities do not agree with the utilities depicted on the design plans. Contractors know this will happen and typically increase their bid price to account for this contingency. They will also ask for change orders and claims when necessary. Usually the project owner is obligated to pay these change orders and claims due to utilities being treated as a differing or unknown site condition in the standard contract documents. STA implementing a process of determining if SUE is required earlier in a project will only reduce contractor risk.

There are numerous benefits for a risk based SUE guidance process on highway projects. By using SUE, significant benefits are derived for the DOT, utility companies, SUE consultants, contractors, and the general public. Some of the benefits that have been obtained are as follows:

• DOT Quality: electronic mapping accuracy, concept of a comprehensive SUE process, improved risk management, improved project productivity and quality, minimize environmental damage;

• DOT time savings: less unforeseen utility conflicts, relocations, delays due to utility cuts, elimination of duplicate surveys;

• DOT Cost savings: lower project bids, lower project contingency fees, project design less conflict redesign, claims, change orders, Right-of-Way acquisition costs, and lowered insurance;

• Public Benefits: reduced motoring public travel delays during construction, less damage to existing pavements, less utility customers' loss of service, less traffic disruption, increasing DOT confidence;

• Stakeholder benefits: reduced utility companies' cost to repair damages, improved working relationships with utilities;

Implementation Considerations

The use of inaccurate utility data contributes to billions of wasteful spending in the U. S. caused by utility and highway coordination. With few exceptions, the public bears the cost of utility delays in form of traveler costs, added transportation costs in retail products, loss of business efficiency (resulting in higher costs and lower profits), and fewer public dollars available to spend on a variety of project needs. With the advantages of 3D design and BIM being explored at STAs, this research is imperative to analyzing conflicts with improved confidence in the associated risks.

Recommended Research Funding and Research Period

The estimated cost is $350,000 and duration is 18 months. The research will complete the following tasks:

1. Review related literature, including best practices in SHRP2 products RO1A, R15B & ASCE 38.

2. Survey stakeholders, including STAs and consultant design firms.

3. Identify STAs with utility record data and or SUE QLA data available for analysis and request data.

4. Examine STA data and develop appropriate statistical models.

a. 100 data points per facility type sourced from case studies, for gas lines, water lines, underground electric lines, and communication lines.

5. Analyze STA data using statistical models.

6. Develop draft guidance documents.

7. Conduct an exploratory workshop to collect feedback on draft guidance documents.

8. Refine and finalize guidance documents.

Note: The research should have a focus on sharing information with potential bidders with the goal that utility risks during construction are better understood, potentially lowering construction bids.

Problem Statement Author(S): For each author, provide their name, affiliation, email address and phone.

Alexis Kinter, PE, PMP, Michigan DOT Metro Quality/Contracts , KinterA@michigan.gov

Potential Panel Members: For each panel member, provide their name, affiliation, email address and phone.

Bill Jackson, Maryland DOT Assistant Statewide Utility Engineer, Office of Construction

wjackson2@mdot.maryland.gov

Person Submitting The Problem Statement: Name, affiliation, email address and phone.

Rob Martindale, PLS, Utilities Program Manager, II, Colorado Department of Transportation

Rob.martindale@state.co.us