The size and mass of the private vehicle fleet in the United States have increased over time due to many factors, including prioritization of vehicle occupant safety, vehicle standards, and consumer preference. Studies have consistently found that pedestrians are likely to sustain greater injury from an SUV than a car, particularly at higher speeds. While larger, heavier vehicles increase injury risk for people walking, bicycling, and rolling in the event of a crash, there are still unanswered questions...

Researchers, policymakers, practitioners, and transportation-industry leaders are exploring how additive manufacturing (commonly referred to as 3D printing) and construction technologies can accelerate innovation in transportation infrastructure. Among the impacts being evaluated are supply chains, logistics, infrastructure resilience, and workforce development. Transportation Research Circular E-C304: TRB Conference on Advancing Additive Manufacturing and Construction in Transportation , from the Transp...

Transportation agencies and the industry in North America are migrating to an approach known as Balanced Mix Design, wherein proposed asphalt mixtures are held to physical property standards based on the results of mixture performance testing. This approach has been used successfully for high-volume roads in Europe for decades. Transportation Research Circular E-C303: The Effect of Asphalt Supply on Balanced Mix Design , from the Transportation Research Board, compiles presentations made during Workshop ...

Access Management is defined as “the coordinated planning, regulation, and design of access between roadways and land development.” Transportation Research Circular E-C301: Access Management Safety and Design from the Curb to the Interchange for All Users contains extended abstracts from selected presentations presented at the Transportation Research Board 4th International/13th National Conference on Access Management, held June 24-26, 2024, in Boston, MA.

Transportation Research Circular E-C302: 2nd Conference on Advancing Transportation Equity , from the Transportation Research Board, summarizes the presentations and discussions from this event held July 15–18, 2024, in Baltimore, Maryland.

Simulation has become a crucial tool for evaluating the effectiveness of proposed capital investments aimed at improving transportation system performance. Factors such as persistent congestion, complex facility operations, and the rapid advancement of technologies and transportation systems management strategies have required agencies to invest in developing and utilizing simulation models. TR Circular E-C298: Transportation Systems Simulation Compendium , from the Transportation Research Board, provide...

Asphalt mix design has always been considered a balance of rutting resistance and durability. The conventional Superpave mix design system targets 4% air voids during design and is referred to in this circular as Superpave4. The Superpave5 concept is a modification to the conventional Superpave4 approach. Transportation Research Circular E-C300: Superpave5: How Increasing Air Voids Can Improve Asphalt Pavement Durability , from the Transportation Research Board, captures information exchanged during the ...

The most inherent advantage of a smooth pavement surface is its reduced noise levels compared to a pavement that is not smooth, but beyond the noise impacts there lies indirect and direct benefits that people gain from a smooth pavement. Transportation Research Circular E-C297: Concrete Pavement Smoothness: 2023 Workshop , from the Transportation Research Board, was developed from presentations made during the 102nd TRB Annual Meeting in a workshop titled "Concrete Pavement Smoothness."

Federal laws and rules require performance standards to be implemented to enhance stewardship of the transportation infrastructure and foster greater innovation in delivering a resilient transportation system, including the life of pavement systems, that supports prosperity and opportunity. Transportation Research Circular E-C296: Foundation Design and Construction for 100-Year Pavement Systems documents the presentations and discussions from two workshops held during the 2024 and 2023 TRB Annual Meeting...

Asphalt mixture mechanical tests (such as Hamburg Wheel-Track, Asphalt Pavement Analyzer, Indirect Tensile Cracking) are growing in use by numerous state departments of transportation (DOTs) as part of their standard material specifications to complement volumetric properties and help ensure satisfactory asphalt mixture performance. Transportation Research Circular E-C294: Adjustment to Asphalt Mixtures to Meet Performance Testing Requirements and Allow Innovations , from the Transportation Research Boar...