Fundamentally changing the culture of a transportation agency and integrating those changes into historically siloed management practices, requires the earnest focus of the entire organization, including participation of practically every individual. The TRB National Cooperative Highway Research Program's pre-publication draft of NCHRP Research Report 985: Integrating Effective Transportation Performance, Risk, and Assessment Management Practices is designed to be a process framework that is resilient to...

Traffic-associated fatigue damage is one of the major distresses in which flexible pavements fail. This type of distress is the result of many thousands—or even millions of wheel loads passing over a pavement. The TRB National Cooperative Highway Research Program's pre-publication draft of NCHRP Research Report 982: Relationships Between the Fatigue Properties of Asphalt Binders and the Fatigue Performance of Asphalt Mixtures details these relationships and makes several conclusions and recommendations.

CEOs of departments of transportation (DOTs) face many challenges, including some that will have serious impacts on people's mobility and safety, and possibly on the tenure of CEOs. Many of these challenges revolve around the resilience of the transportation system—how well it can withstand disruptions from natural causes, catastrophic failures of the infrastructure or cyber events, and how quickly the agency can restore services when they are impacted. The TRB National Cooperative Highway Research Progr...

Light emitting diode (LED) technology has revolutionized the lighting industry. The dimming and instant-on capabilities of these light sources along with their high efficiency have allowed lighting designers to overcome some of the limitations of previous technologies, particularly in roadway lighting environments. However, concerns related to the health and environmental impacts of LEDs have been raised. The TRB National Cooperative Highway Research Program's NCHRP Research Report 968: LED Roadway Light...

Bridge waterways commonly narrow or constrict natural channels, forcing water to flow through a contracted area, thereby increasing the magnitudes of velocity and turbulent kinetic energy of flow passing through the waterway. If these increases cause erosion of the waterway boundaries, the contracted section may scour. The TRB National Cooperative Highway Research Program's NCHRP Research Report 971: Revised Clear-Water and Live-Bed Contraction Scour Analysis develops live-bed and clear-water contraction...

Prior to 1976, federal highway funds could only be used for the construction of new highways or the reconstruction of existing highways. The Federal-Aid Highway Act of 1976 allowed the use of federal aid for resurfacing, restoration, and rehabilitation (3R) projects on federal-aid highways. However, in 1976 there were no standards for 3R improvements. The TRB National Cooperative Highway Research Program's  NCHRP Research Report 876: Guidelines for Integrating Safety and Cost-Effectiveness into Resu...

Transportation officials recognize that a reliable and sustainable transportation system is needed to fulfill their agency’s mission and goals. The TRB National Cooperative Highway Research Program's NCHRP Research Report 970: Mainstreaming System Resilience Concepts into Transportation Agencies: A Guide provides transportation officials with a self-assessment tool to assess the current status of an agency’s efforts to improve the resilience of the transportation system through the mainstreaming of resil...

Macrotexture, which influences vehicle-roadway skid resistance, refers to the texture of the pavement due to the arrangement of aggregate particles. Pavement surfaces are subjected to seasonal variations, and over time the embedded aggregates become polished due to the onslaught of traffic. Research has shown that wet-weather crashes are influenced by the macrotexture of the pavement surface. The TRB National Cooperative Highway Research Program's NCHRP Research Report 964: Protocols for Network-Level Ma...

Structural supports for signs, luminaires, and traffic signals and other steel highway structures are generally galvanized to prevent corrosion and provide a long service life. However, recent investigations have revealed incidents of cracking in weldments of galvanized structures that appear to be induced during the galvanizing process. The TRB National Cooperative Highway Research Program's NCHRP Research Report 965: Mitigation of Weldment Cracking in Steel Highway Structures Due to the Galvanizing Pro...

Several factors are considered within engineering studies when determining the posted speed limit, including the 85th percentile speed, which is based on the driving behavior of most drivers (85 percent). The 85th percentile speed is believed to represent a safe speed that would minimize crashes. The TRB National Cooperative Highway Research Program's NCHRP Research Report 966: Posted Speed Limit Setting Procedure and Tool: User Guide provides and explains a speed limit setting procedure (SLS-Procedure) ...