Transportation Research Board
HomeContact Us Directory E-NewsletterFollow Us RSS

The National Academies
Publications > Highway (NCHRP) > Research Results Digests
Text Size: Increase Text SizeDecrease Text Size| Share:


National Cooperative Highway Research Program (NCHRP) Research Results Digests (RRDs)

RRDs are used to promote early awareness of project results in order to encourage implementation. RRDs also summarize specific findings that emphasize how the research may be used. The contents are organized in terms of the problem and the solution to it, the findings, and the applications. RRDs generally run 4–32 printed pages.

Below are the latest 20 NCHRP Research Results Digests that have been produced by TRB.  A page highlighting NCHRP Research Results Digests that have been released since June 2001 is available online.  To search for older publications visit the TRB Online Bookstore or the TRB Publication Index.


 
Guidebook for Construction Management Practices for Rural ProjectsGuidebook for Construction Management Practices for Rural Projects
March 27, 2013
TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 381: Guidebook for Construction Management Practices for Rural Projects focuses on tools and techniques that may be used to help improve aspects of construction management in the rural environment. Tools and techniques covered in the report address issues such as construction administration, engineering, op...
Selected State DOT Cost Reduction Initiatives for the Administration of State Public Transportation ProgramsSelected State DOT Cost Reduction Initiatives for the Administration of State Public Transportation Programs
January 17, 2013
TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 379: Selected State DOT Cost Reduction Initiatives for the Administration of State Public Transportation Programs explores the potential impact of employee layoffs, furloughs, and hiring and travel freezes on the administration of public transportation programs. The report also examines costs incurred by state d...
Evaluation of Bridge Scour ResearchEvaluation of Bridge Scour Research
September 17, 2012
TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 378: Evaluation of Bridge Scour Research summarizes key finding of three NCHRP projects that explored processes and predictions related to pier scour, abutment and contraction scour, and geomorphic scour. The results of the three research projects summarized in NCHRP RRD 378 were each published separately in the...
Continuing Project to Synthesize Information on Highway Problems: 2013Continuing Project to Synthesize Information on Highway Problems: 2013
February 4, 2013
TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 377: 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.”
Data Needs for Assessing Rural Transit Needs, Benefits, and Levels of ServiceData Needs for Assessing Rural Transit Needs, Benefits, and Levels of Service
September 14, 2012
TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 376: Data Needs for Assessing Rural Transit Needs, Benefits, and Levels of Service assesses the data elements that are available through the Rural National Transit Database and identifies levels of service options that are potentially more accurate or useful for future evaluation of rural service.
Rural Public Transportation Strategies for Responding to the Livable and Sustainable Communities InitiativeRural Public Transportation Strategies for Responding to the Livable and Sustainable Communities Initiative
June 29, 2012
TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 375: Rural Public Transportation Strategies for Responding to the Livable and Sustainable Communities Initiative explores ways that state departments of transportation may help rural organizations advance transit-related solutions to rural mobility challenges.
A Proposed Technology Evaluation Program for Warm-Mix AsphaltA Proposed Technology Evaluation Program for Warm-Mix Asphalt
August 20, 2012
TRB’s National Cooperative Highway Research Program (NCHRP) Research Result Digest 374: A Proposed Technology Evaluation Program for Warm-Mix Asphalt summarizes the key findings of a project that was charged with defining a warm-mix asphalt technology evaluation program that would be compatible with a centralized system of testing, evaluation, and data reporting of engineering materials for the...
A Toolkit for Reporting Rural and Specialized Transit Data--Making Transit CountA Toolkit for Reporting Rural and Specialized Transit Data--Making Transit Count
August 31, 2012
TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 373: A Toolkit for Reporting Rural and Specialized Transit Data—Making Transit Count presents the results of an analysis of automated transit data collection and analysis procedures in state department of transportation transit units. The report also provides a toolkit for next-generation transit data analysis f...
Sensitivity Evaluation of MEPDG Performance PredictionSensitivity Evaluation of MEPDG Performance Prediction
April 5, 2013
TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 372: Sensitivity Evaluation of MEPDG Performance Prediction summarizes the results of a study that evaluates the sensitivity of pavement performance predicted by the Mechanistic-Empirical Pavement Design Guide (MEPDG) to the values of the design inputs.
Quality-Related Pay Adjustment Factors for PavementsQuality-Related Pay Adjustment Factors for Pavements
January 31, 2013
TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 371: Quality-Related Pay Adjustment Factors for Pavements offers guidance pertaining to the quality-related pay adjustment factors used for flexible and rigid pavement construction.
Guidelines for Project Selection and Materials Sampling, Conditioning, and Testing in WMA Research StudiesGuidelines for Project Selection and Materials Sampling, Conditioning, and Testing in WMA Research Studies
February 29, 2012
TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 370: Guidelines for Project Selection and Materials Sampling, Conditioning, and Testing in WMA Research Studies summarizes a May 2011 workshop designed to help foster cooperation and coordination among warm-mix asphalt (WMA) research studies. The goals of the workshop were to help identify the laboratory and fie...
AASHTO T 209: Effect of Agitation Equipment Type on Theoretical Maximum Specific Gravity ValuesAASHTO T 209: Effect of Agitation Equipment Type on Theoretical Maximum Specific Gravity Values
February 17, 2012
TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 369: AASHTO T 209: Effect of Agitation Equipment Type on Theoretical Maximum Specific Gravity Values evaluates the effect of using various devices and methods on measured values of theoretical maximum specific gravity (Gmm) used to determine the air void content and the in-place density of hot-mix asphalt (HMA) ...
State DOT Financial Auditing Requirements for Public Transportation Assistance ProgramsState DOT Financial Auditing Requirements for Public Transportation Assistance Programs
March 26, 2012
TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 368: State DOT Financial Auditing Requirements for Public Transportation Assistance Programs identifies various financial policies and procedures used by states for conducting grantee financial audits. The report documents policies, procedures, and practices used by some state departments of trans...
Continuing Project to Synthesize Information on Highway Problems: 2012Continuing Project to Synthesize Information on Highway Problems: 2012
February 9, 2012
TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 367: 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.”
Local and State Partnerships with Taxicab CompaniesLocal and State Partnerships with Taxicab Companies
February 6, 2012
TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 366: Local and State Partnerships with Taxicab Companies discusses how states and local governments might promote partnerships with taxicab companies for provision of public transportation. In the context of the report, a “partnership” typically involves some form of contract for service, but also includes less ...
Sustainable Pavement Maintenance PracticesSustainable Pavement Maintenance Practices
January 19, 2012
TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 365: Sustainable Pavement Maintenance Practices highlights the current practice in sustainable pavement maintenance and preservation. The report is designed to help quantify and understand how pavement maintenance and preservation practices minimize environmental impacts. As part of the development of this repor...
Validation of LRFD Metal Loss and Service-Life Strength Reduction Factors for Metal-Reinforced SystemsValidation of LRFD Metal Loss and Service-Life Strength Reduction Factors for Metal-Reinforced Systems
October 11, 2011
TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 364: Validation of LRFD Metal Loss and Service-Life Strength Reduction Factors for Metal-Reinforced Systems summarizes the results of research to further validate some key results of a project that resulted in publication of NCHRP Report 675: LRFD Metal Loss and Service-Life Strength Reduction Factors for Metal-...
Hydroacoustic Impacts on Fish from Pile InstallationHydroacoustic Impacts on Fish from Pile Installation
October 26, 2011
TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 363: Hydroacoustic Impacts on Fish from Pile Installation explores the prediction and mitigation of the negative impacts on fish from underwater sound pressure during pile and casing installation and removal.  Appendices A through H for RRD 363 are available online.
Review of Mexican Experience with the Regulation of Large Commercial Motor VehiclesReview of Mexican Experience with the Regulation of Large Commercial Motor Vehicles
October 28, 2011
TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 362: Review of Mexican Experience with the Regulation of Large Commercial Motor Vehicles reviews and summarizes the Mexican experience with changes in truck size and weight limits. The report also evaluates the potential applicability to size and weight limits in the United States.
State DOT Public Transportation Performance Measures: State of the Practice and Future NeedsState DOT Public Transportation Performance Measures: State of the Practice and Future Needs
October 6, 2011
TRB’s National Cooperative Highway Research Program (NCHRP) RRD 361: State DOT Public Transportation Performance Measures: State of the Practice and Future Needs includes information on performance measures and performance management approaches that may be used by state departments of transportation (DOTs) in relation to public transportation programs.


More.....