The American Association of State Highway and Transportation Officials (AASHTO) and TRB's National Cooperative Highway Research Program (NCHRP) have initiated a multi-year process to describe and advance the implementation of a vision for the next era of transportation in the United States. NCHRP Research Results Digest 404: Collective and Individual Actions to Envision and Realize the Next Era of America’s Transportation Infrastructure: Phase 1 , from NCHRP, explores and articulates what state DOTs can ...

The Federal Transit Administration’s Enhanced Mobility of Seniors and Individuals with Disabilities program (49 U.S.C. 5310) provides formula funding to help private nonprofit groups meet the transportation needs of older adults and people with disabilities when existing transportation service is unavailable, insufficient, or inappropriate. The TRB National Cooperative Highway Research Program's NCHRP Research Results Digest 403: Program Management Insights for the Section 5310 Program, Including Subreci...

TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 402: Continuing Project to Synthesize Information on Highway Problems provides a 2018 update on current knowledge and practice, in a compact format, without the detailed directions usually found in handbooks or design manuals. Each report in the series provides a compendium of the best knowledge available on those measures found to be most successful in resolving specific problems.

TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 401: Continuing Project to Synthesize Information on Highway Problems is a digest of the progress and status of NCHRP Project 20-5, “Synthesis of Information Related to Highway Problems.”

TRB's National Cooperative Highway Research Program (NCHRP) Research Results Digest 400: Sample Size Implications of Multi-Day GPS-Enabled Household Travel Surveys summarizes an NCHRP project that studied the design of household travel surveys. Multi-day travel surveys are now more feasible, given global positioning system (GPS) technology. This project explores if surveys using a GPS device provides less drop-off in response compared to travel diaries. This project also investigates the effects of using...

TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 399: Field Validation of Laboratory Tests to Assess Cracking Resistance of Asphalt Mixtures: An Experimental Design develops an experimental design, including a proposed schedule and budget, for the field validation of laboratory tests selected under this study to assess the potential for the four types of cracking of asphalt mixtures—thermal, reflection, bottom-up fatigue, and top-down. In the past, volumetric mixture de...

TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 398: Continuing Project to Synthesize Information on Highway Practices is a digest of the progress and status of NCHRP Project 20-5, “Synthesis of Information Related to Highway Practices.”

TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 397: Independent Cost Estimates for Design and Construction of Transit Facilities in Rural and Small Urban Areas explores the distinct characteristics of rural and small urban area transit facilities and historical cost data. The report includes a prototype tool that may assist agencies with preparing conceptual estimates. The prototype tool is offered as is, without warranty or promise of support of any kind either expre...

TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 396: Approach to Level-of-Service Target Setting for Highway Assets identifies methodologies and provides guidance for selecting level-of-service targets  for maintaining and operating highway assets. In the past, targets have often been established based on the expert opinion of individuals and have not necessarily followed a systematic process. In addition to the digest, the report includes: The contractor’s Guide ...

TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 394: Estimating the Long-Term Impacts of MAP-21 on the Nation’s Local Rural Transit Bus Infrastructure explores an analysis of the long-term impacts of the Moving Ahead for Progress in the 21st Century Act (MAP-21) on the nation’s rural transit infrastructure. This analysis includes a review of funding levels beginning in 2006 provided by federal, state, and local sources for rural transit. It also provides a comparison o...