State transportation agencies (STAs) may need to focus their strategic planning and programmatic initiatives over the next two decades to mitigate threats to, and take advantage of, opportunities for system performance and agency effectiveness. The TRB National Cooperative Highway Research Program's NCHRP Web-Only Document 346: Programmatic Issues of Future System Performance details a unified fra...

Dynamic curbside management has been the purview of cities, with much of the relevant research and guidance directed toward local transportation agencies. However, state departments of transportation, metropolitan planning organizations, and other regional agencies can be important partners for these local entities because, in many cases, roadways and other curb zone elements are part of the regio...

Implements of husbandry (IoH) are vehicles designed for agricultural purposes and exclusively used in the conduct of agricultural operations. The TRB National Cooperative Highway Research Program's  NCHRP Web-Only Document 338: Quantifying the Effects of Implements of Husbandry on Pavements: Appendices is supplemental to   NCHRP Research Report 1019: Quantifying the Effects of Implements...

Crash data show that more than 18,000 traffic fatalities per year result from roadway departures, and over 7,000 of those roadway departure crashes involved collisions with roadside fixed objects. The TRB National Cooperative Highway Research Program's NCHRP Web-Only Document 336: Proposed Guidelines for Fixed Objects in the Roadside Design Guide helps develop an evaluation methodology and design ...

Determining the value of a transportation organization's physical assets is important for both financial reporting and transportation asset management (TAM). The TRB National Cooperative Highway Research Program's NCHRP Web-Only Document 335: A Guide to Computation and Use of System-Level Valuation of Transportation Assets details how to calculate asset value and use it to support application in T...

The TRB National Cooperative Highway Research Program's NCHRP Web-Only Document 334: Roadside Barrier Designs near Bridge Rail Ends with Restricted Rights-of-Way: A National Survey and Testing Reports includes appendices to NCHRP Research Report 1013: Roadside Barrier Designs near Bridge Rail Ends with Restricted Rights-of-Way: A Guide , which describes the application and installation of short-ra...

State departments of transportation (DOTs) face increasingly stringent requirements for stormwater quantity and quality. The TRB National Cooperative Highway Research Program's NCHRP Web-Only Document 333: Watershed Approach to Mitigating Hydrologic Impacts of Transportation Projects: Conduct of Research Report  describes the development of a watershed-based approach to mitigating hydrologic ...

The evolution of roadside hardware in the past has been largely dictated by changes to crash testing guidelines rather than observed field performance. The TRB National Cooperative Highway Research Program's NCHRP Web-Only Document 332: Multi-State In-Service Performance Evaluations of Roadside Safety Hardware develops a unified format and nationally compatible "in-service performance evaluation" ...

With an accessibility perspective, land use changes can bring transportation improvements by bringing activity locations closer together. If incorporated into transportation performance management, accessibility has the potential to highlight projects that would otherwise be overlooked because of their congestion-related impacts. The TRB National Cooperative Highway Research Program's NCHRP Web-On...

The TRB National Cooperative Highway Research Program's NCHRP Web-Only Document 329: Bonded Concrete Overlays on Asphalt Pavements: Resources for Evaluation  provides Appendices A through G of the contractor’s final report, which detail survey responses from transportation agencies on bonded concrete overlays on asphalt pavements as well as agency plans and projects. The document is supplemen...

Across the United States, maximum speed limit laws vary dramatically. In the mid-1990s, many states increased speed limits to 75 mph on select roads. More recently, some states have established speed limits greater than 75 mph. The TRB National Cooperative Highway Research Program's NCHRP Web-Only Document 328: Safety Effects of Raising Speed Limits to 75 mph and Higher is supplemental to NCHRP Re...

Motorcycle riders account for more fatalities than the passengers of any other vehicle type involved in a guardrail collision. The TRB National Cooperative Highway Research Program's NCHRP Web-Only Document 327: Serious and Fatal Motorcycle Crashes into Traffic Barriers: Injury Information is a supplemental document to NCHRP Research Report 1005: Motorcycle Crashes into Traffic Barriers: Factors R...

A major use of Mechanically Stabilized Earth (MSE) walls is as bridge approach embankments, where they are typically constructed with a roadside barrier system supported on the edge of the walls. The TRB National Cooperative Highway Research Program's NCHRP Web-Only Document 326: Design Guidelines for Test Level 3 through Test Level 5 Roadside Barrier Systems Placed on Mechanically Stabilized Eart...

Highway engineers are constantly redesigning and rebuilding roadways to meet higher standards, provide safer highways and increase mobility. For the last forty years this has included designing and building roadways that are more forgiving when a driver inadvertently encroaches onto the roadside. The TRB National Cooperative Highway Research Program's NCHRP Web-Only Document 325: Consideration of ...

In June 2014, eight associations that represent government agencies involved in highway safety released the document Toward Zero Deaths: A National Strategy on Highway Safety . This national strategy describes a long-term vision of zero traffic-related deaths and outlines the current challenges that need to be tackled. The TRB National Cooperative Highway Research Program's NCHRP Web-Only Document...

The Highway Safety Manual can be used to identify sites with the most potential for crash frequency or severity reduction; identify contributing factors to crashes and mitigation measures; and estimate the potential crash frequency and severity on highway networks, among other uses. The TRB National Cooperative Highway Research Program's NCHRP Web-Only Document 323: Highway Safety Manual User Guid...

Work zone intrusion technologies are available that provide an opportunity to prevent and mitigate vehicle intrusions into roadway work zones. The TRB National Cooperative Highway Research Program's NCHRP Web-Only Document 322: Alternative Technologies for Mitigating the Risk of Injuries and Deaths in Work Zones: Conduct of Research provides a comprehensive synthesis and evaluation of technologies...

Command-level decision making is a critical factor in successfully managing and mitigating critical incidents.  The TRB National Cooperative Highway Research Program's NCHRP Web-Only Document 321: Command-Level Decision Making for Transportation Emergency Managers is a document done in collaboration with TRB's Transit Cooperative Research Program (TCRP) and Airport Cooperative Research Progra...

Since 1984, AASHTO’s “Green Book” and other roadway design criteria have been primarily based on a functional classification system of a hierarchical network composed of arterials, collector, and local roads. However, this hierarchical functional classification system is in lack of flexibility in design, especially for a modern multimodal roadway system. The TRB National Cooperative Highway R...

Motor vehicle crashes cost society more than $230 billion annually. On an average day, 117 fatal crashes occur on U.S. roadways, and 30 percent of these fatalities are people under the age of 25. In total, this amounts to a societal loss of $630 million per day. The TRB National Cooperative Highway Research Program's NCHRP Web-Only Document 319: Roadside Safety Analysis Program (RSAP) Update detai...