Document Library

This publication explains how the FHWA Long-Term Pavement Performance (LTPP) database underpins modern pavement performance modeling and performance-based investment decisions. For practitioners, it outlines how LTPP data are used to calibrate and validate Pavement ME design procedures, establish national data collection standards, and support statistically robust performance comparisons under real-world conditions. Agencies interested in strengthening pavement performance forecasting, improving lifecycle cost estimates, or validating local design assumptions will find this a useful overview of available data tools and access points.

Artificial intelligence (AI), digitalization, and advanced automation are separate but closely connected technological fields. Together, they offer extraordinary opportunities to strengthen, reshape, and even transform the transportation enterprise. Leveraging the power and possibilities of all three technologies and their synergies will be an ongoing endeavor in the transportation field.

A product of the TRB Executive Committee, Transforming Transportation: Leveraging the Power of Artificial Intelligence, Digitalization, and Automation aims to inspire and encourage the community of transportation practitioners and researchers, to take an active role in exploring and advancing these possibilities, which are only beginning to take shape.

NCHRP Research Report 1167: Interdependence of Federal, State, and Local Transportation Funding and Ownership, produced by TRB’s National Cooperative Highway Research Program, is designed to provide an overview of interdependent funding in the transportation community, the strategies used to manage it, and the outcomes of funding interdependences. Policy- and decision-makers can use the report to help calibrate contextual decisions about generating and using transportation funding in an interdependent environment. The report also gives decision-makers an understanding of both broad approaches and specific strategies that agencies at all levels of government are using to navigate interdependent transportation funding.

TRB Special Report 360: Managing Highway Stormwater Quality: Driving Progress focuses on engineering and infrastructure strategies to support state departments of transportation (DOT) decision-making regarding stormwater management approaches to comply with regulations. Administered by the U.S. Environmental Protection Agency (EPA), state permitting authorities identify each water body that does not meet a water quality standard due to pollutants.

Updated modeling options that account for different land uses can better enable state DOT decision makers. Acknowledging the difference in pollutants that originate from highways (such as tire and brake wear contaminants) and pollutants that do not but are conveyed to water bodies (such as nutrients and bacteria from adjacent land) may improve source control.

The report also identifies areas for collaboration between state DOTs, EPA, and Federal Highway Administration officials along with state environmental authorities. These partnerships could result in improved design, construction, and maintenance procedures and guidance. Participation in alternative watershed-scale approaches for managing highway stormwater may also result in practical and desirable outcomes.

This report provides key HR metrics from state departments of transportation (DOTs) that responded to a survey developed by the AASHTO Committee on Human Resources. In the survey, state DOTs were asked to provide information on employee counts and tenure, turnover and retirement, telework, and diversity data, both for the entire agency and broken down by EEO position categories. The collection and reporting of this data is designed to create a uniform set of metrics to inform nationwide policies, processes, and best practices. This report updates data collected for the 2023 Annual AASHTO State DOT HR Metrics Report, published in 2024.

Throughout its more than 25-year history, the Transit Capacity and Quality of Service Manual (TCQSM) has compiled the state of the practice based on peer-reviewed research published by the Transportation Research Board and others. The TCQSM provides transportation practitioners of varying levels of experience and responsibility information, techniques, and resources to support the planning, design, and operation of transit services, facilities, and systems. While the TCQSM’s methods represent the best available knowledge at the time of publication, they do not establish policies regarding desirable or appropriate levels of quality of service or capacity for transit services, facilities, or systems.

TCRP Research Report 262: Transit Capacity and Quality of Service Manual, 4th edition, includes updated statistics, transit agency application examples, and photographs. The manual incorporates emerging mobility options such as microtransit and low-speed automated vehicles, with expanded coverage of widely adopted technologies such as bus and ferry electrification. This edition updates key concepts related to modes and services, operations, and quality of service. Additional updates address topics including quality of service measures and applications, bus transit, demand-responsive transit, rail transit, ferry transit, and transit stops and stations.

Truck parking is a nationwide issue that has intensified with the growth of e-commerce and freight demand. Although federal and state agencies assess needs and construct rest areas, local governments strongly influence parking availability through land use policies, zoning, and enforcement. Safe and adequate truck parking supports freight efficiency, roadway safety, and public health; yet many local jurisdictions lack the resources and guidance needed to address this issue proactively.

NCHRP Research Report 1175: Developing a Guide for Local Truck Parking Regulations, produced by TRB’s National Cooperative Highway Research Program, explores the factors influencing local truck parking decisions, identifies associated challenges and opportunities, and provides actionable resources to help local governments plan for and regulate truck parking more effectively.

The project that led to NCHRP Research Report 1175 also produced NCHRP Web-Only Document 446: Guide for Local Truck Parking Regulations. This companion guide presents a solutions toolbox and a range of model truck parking and staging ordinances, rules, and regulations suitable for consideration and adoption by local municipalities. The guide also addresses truck parking needs, as well as funding opportunities and related resources.

A guide describing the process of integrating telematics risk analysis to improve safety planning and decision-making. TRA uses physics and AI-based tools to measure patterns of risk on the road. Unlike traditional traffic safety data systems that rely on historical trends, TRA analyzes roadway behaviors, such as phone handling, speeding, hard braking, and aggressive cornering as they are happening. This anonymized, aggregated information is then combined to form predictive safety indicators and assess risk. Insurance companies have used this process to predict risks for decades. The same opportunity to better predict risk and make smarter choices on how to prevent crashes and save lives is now available to the highway safety community. By tracking actual patterns of risk, SHSOs can actively deploy TRA to build, implement, and evaluate their THSPs.

For this report, new mobility services are defined as innovative transportation services that redefine how people and goods move within the existing transportation system. Examples include micromobility (shared bikes and scooters), car-sharing, ride-hailing, microtransit, and modern goods delivery services. Revenue measures applied to new mobility services can help agencies that own and manage the transportation system fund staff, technology improvements, and right-of-way modifications. Pricing strategies can also help manage demand for both the services themselves and the public spaces they use. Some new mobility services may merit subsidies because they advance community transportation goals. However, decision-makers are often unaware of the full range of revenue-related tools available to them.

NCHRP Research Report 1165: Revenue-Related Tools for New Mobility, produced by TRB’s National Cooperative Highway Research Program, includes a decision-making framework and examples of best practices to assist those who manage or fund surface transportation networks as they explore ways to subsidize, charge, or assess new mobility services. The report describes the framework for evaluating revenue-related tools for new mobility and explains how to apply the framework. The report also examines promising and innovative revenue models.

Shared-use mobility (SUM) services—commonly associated with urban areas—encompass ridesharing, carsharing, ride-hailing, microtransit, mobility-on-demand, vanpool services and systems, and other forms of transportation shared among users. However, small urban, rural, and frontier areas interested in implementing SUM services to improve mobility and accessibility in their communities face challenges such as limited transportation options, greater travel distances, fewer resources, and minimal infrastructure.

NCHRP Research Report 1171: Public Transit and Ride Sharing for Rural, Tribal, and Frontier Agencies: A Guide, produced by TRB's National Cooperative Highway Research Program, explores the integration of SUM services with public transportation options in less-populated areas. The guide synthesizes notable SUM practices and lessons learned from transit agencies and other transportation providers. Topics addressed in the guide include goal setting, local coordination, policy development, regulations and permitting, service partnerships, technology and infrastructure, marketing and customer education, and performance measures.

The full research effort behind NCHRP Research Report 1171 is documented in NCHRP Web-Only Document 443: Public Transit and Ride Sharing for Rural, Tribal, and Frontier Agencies: Research into Coordination.

Many women’s travel experiences relate directly to their disproportionate share of caregiving responsibilities. Travelers supervising dependents are more likely to need access to multiple destinations and may have more belongings in tow. Because dependents are unlikely to be commuting adults, travel during off-peak hours is more common, and paying multiple fares can increase the financial burden. Additionally, safety is a greater concern for women, both when they are traveling alone and when they are traveling with dependents, especially children.

TCRP Research Report 265: Addressing Travel Needs of Women and Families on Public Transportation, produced by TRB’s Transit Cooperative Research Program, presents a set of practical tools to help transit agencies better understand their riders, use existing data more effectively, assess how well they are serving women and families, build internal support for these efforts, and identify service planning, vehicle, and station design strategies that benefit women and families. The eight tools are organized into three stages: Understand Your Riders, Build Internal Capacity, and Deploy Your Tactics.

Subsurface utilities, buried from inches to many feet below roadways and rights-of way, pose significant challenges because they are not visible and cannot be assessed through visual inspection. Their location, condition, ownership, and impact on cost and schedule must instead be determined through specialized investigation methods and stakeholder coordination. Utility data depiction is the primary means of communication, yet it is often inconsistent, with varying stakeholder expectations.

NCHRP Research Report 1180: Depicting Utility Facilities in Design Plans: A Guide, produced by TRB’s National Cooperative Highway Research Program, provides a set of guidelines for transportation agencies on depicting utility data from various sources. These guidelines support design decision-making, utility conflict identification and resolution, and consistent depiction practices. The scope includes both existing and proposed utility facilities. The guide is intended to support both 2-D and 3-D formats, recognizing that agencies vary in their access to and proficiency with different software tools.

The same project that developed NCHRP Research Report 1180 also produced NCHRP Web-Only Document 449: Developing a Guide to Depicting Utility Facilities in Design Plans. This companion document summarizes the research conducted to develop the guide.