Document Library

NCHRP Research Report 1149: Estimating Benefits of Closing Gaps in Active Transportation Networks: A Guide provides practical methods for evaluating the benefits of projects that improve connectivity in walking, bicycling, and rolling networks. Active transportation systems—including trails, sidewalks, bike lanes, and connected roadways—play a critical role in supporting safe, convenient travel for both recreation and everyday trips, yet many communities face fragmented networks with significant gaps. This guide offers accessible analytical approaches that can be applied across diverse geographies and project types, using publicly available datasets and research-based multipliers. Designed for broad usability, the methods rely primarily on national-level data sources to help agencies consistently estimate economic, safety, health, and mobility benefits.

NCHRP Web-Only Document 426, which accompanies the report, documents the development of the guide and summarizes the full research effort behind the recommended methodologies.

NCHRP Research Report 1164: The Business Case for Knowledge Management: A Guide provides state departments of transportation and other transportation agencies with practical tools to assess and measure the value of knowledge management (KM) initiatives. As experienced staff retire and collaboration across disciplines increases, agencies face growing challenges in preserving institutional knowledge and ensuring effective knowledge transfer. The guide outlines approaches for evaluating how KM practices contribute to improved business processes, workforce development, and organizational performance. It helps agencies articulate the return on investment of KM activities and integrate them into broader performance management strategies.

Accompanying the report, NCHRP Web-Only Document 437: Assessing and Measuring the Business Value of Knowledge Management documents the research effort and provides additional detail supporting the guide’s development.

Technological change has left many agencies managing numerous legacy systems and disparate architectures that, despite their limitations, remain valuable. To support cross-functional decision-making, some agencies are enhancing these systems by adopting data lake or data warehouse approaches. Advanced data representation and knowledge management techniques, such as developing a data ontology, could improve these strategies. A data ontology is a framework for characterizing and defining classes, attributes, and their relationships in a domain, providing a shared meaning across multiple users.

NCHRP Research Report 1169: Data Ontologies for Data-Driven Decision-Making: Development and Use, produced by TRB’s National Cooperative Highway Research Program, explores the implementation of a conceptual framework designed to help guide transportation agencies in the development and implementation of data ontologies. The report addresses the value of data ontologies from both business and technical perspectives and emphasizes the organizational, functional, and technical needs for successful integration of data ontologies.

Supplemental to the report is NCHRP Web-Only Document 441: Data Ontologies for Data-Driven Decision-Making: Research Approach and Findings.

Pedestrian safety has become an increasing concern in the United States, as significant rises in pedestrian fatalities and injuries have placed a spotlight on efforts to improve safety for people walking to school, to work, or for pleasure. State departments of transportation (DOTs) have implemented a range of pedestrian safety measures, but they continue to face numerous challenges.

NCHRP Synthesis 662: Pedestrian Safety Enhancements by State DOTs, produced by TRB’s National Cooperative Highway Research Program, examines how state DOTs are enhancing pedestrian safety through infrastructure upgrades; crossing and monitoring technologies; and the implementation of relevant policies, regulations, and legislation. The synthesis also highlights public education campaigns, community engagement strategies, speed management efforts, and Safe System approaches. In addition, it documents collaborations with partner agencies, methods used to evaluate safety outcomes, and challenges encountered in implementing pedestrian safety improvements.

The Highway Safety Improvement Program (HSIP) and the State Highway Safety Program are federal initiatives designed to improve highway safety and reduce fatal and serious injuries on the nation’s roadways. HSIPs are typically administered by state departments of transportation (DOTs) and may be structured differently across states. The State Highway Safety Program is managed by Highway Safety Offices (HSOs) in each state, which may be housed within the DOT or in another state agency.

NCHRP Synthesis 661: Coordination of Highway Safety Improvement Program and Highway Safety Office Activities, produced by TRB’s National Cooperative Highway Research Program, explores how states organize, manage, and align their HSIPs and HSOs. The report examines existing coordination of these functions through shared planning, data exchange, performance measures, and reporting processes. It also documents coordination practices related to funding, safety program implementation, public participation and engagement efforts, and the use of data tools and dashboards.

Before the 1960s, rural communities had little influence over transportation planning, despite substantial state and federal investment in rural infrastructure. Over time, federal policy emphasized greater rural participation, encouraging state departments of transportation (DOTs) to adopt planning approaches in nonmetropolitan areas that engaged communities and local officials. Early efforts focused on consultation with rural officials and the use of regional planning entities (RPEs) as intermediaries. Congress later authorized the designation of Regional Transportation Planning Organizations (RTPOs) for non-metropolitan planning. Although few RTPOs have been formally designated, many state DOTs work with RPEs or similar organizations that perform RTPO-like functions. These entities are now important partners in rural planning, though their roles and relationships with state DOTs vary across states.

NCHRP Synthesis 663: Transportation Planning in Non-Metropolitan/Rural Areas, produced by TRB’s National Cooperative Highway Research Program, highlights strategies employed by state DOTs to ensure effective coordination with non-metropolitan officials. The report covers governance and rural planning structures; roles and responsibilities; cooperation with local officials; capacity building; transit and multimodal planning; and key challenges and barriers. It also identifies observed practices that may support effective coordination and areas where additional research is needed.

State departments of transportation (DOTs) have effective procurement processes for highway construction but lag in acquiring new business technologies. As they invest in advanced solutions for communications, asset management, and human resources, they aim to leverage artificial intelligence and cloud-based big data tools. However, traditional procurement methods typically relied on by state DOTs focus on individual purchases rather than long-term goals and often fall short in addressing the growing complexity of these systems and evolving customer needs. This can create challenges in acquiring technological products and services.

NCHRP Research Report 1145: Practices for Transportation Agency Procurement and Management of Advanced Technologies, from TRB's National Cooperative Highway Research Program, presents a guide that includes successful strategies and practices for procuring new and innovative transportation system technologies.

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.