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In this paper we provide a simple and intuitive story for supply chain disruptions driven by the rigidities in the transportation sector. Focusing on maritime shipping, we argue that the frequent macroeconomic shocks that shape demand for transportation, meet a highly inelastic supply curve for transportation services. The steepness is driven by equilibrium bottlenecks in […]
State transportation agencies have many tools available with which to maintain pavements proactively. These include tools such as pavement management systems to track roadway conditions and life cycle cost analysis tools. NCHRP Synthesis 623: Wintertime Pavement Maintenance Practices, from TRB’s National Cooperative Highway Research Program, documents the current state DOT practices for the reactive pavement […]
This report builds on the foundation established by three earlier congressional reports required under the Fixing America’s Surface Transportation Act (FAST Act), enacted in 2015. Section 24104 mandated biennial analyses of vehicle safety recall completion rates, culminating in the submission of the final required report in compliance with this directive in 2020. These reports incorporated […]
This study examined the degree to which an in-vehicle signal countdown timer influenced human drivers’ intersection approaching behaviors and decisionmaking. Secondarily, the study compared intersection approaching behaviors between human drivers and automated shuttles. The research team further simulated predicted behaviors of human drivers at lower speeds and predicted behaviors of shuttles at higher speeds. The […]
TRB’s National Cooperative Highway Research Program (NCHRP) Research Report 889: Performance Measures in Snow and Ice Control Operations presents approaches for monitoring the performance of snow and ice control activities by public agencies and proposes a core set of performance measures that can be customized and used by agencies to meet their snow and ice […]
This document summarizes the highway infrastructure resilience framework and practices for PostEvent Damage Inspection (PDI) and Post-Event Engineering Investigation (PEI) developed under the FHWA Task Order “Framework for Infrastructure Resilience and Post-Hazard Response.” The document describes the framework components: pillars, lenses, dimensions and indicators. It outlines the steps suggested for the evaluation of the resilience […]
State departments of transportation (DOTs) are responsible for the construction and maintenance of the nation’s roadway infrastructure, which requires quality materials and workmanship verified through inspection and testing. NCHRP Synthesis 638: State DOT Certification Programs for Materials Sampling and Testing Personnel, from TRB’s National Cooperative Highway Research Program, documents practices used by DOTs for implementing […]
Transportation is fundamental to the vibrancy of the Nation and facilitates economic prosperity and quality of life. It enables people to engage in productive pursuits and experience the social interactions that take full advantage of geographic specialization and diffusion. An efficient and resilient transportation system and its seamless operation underpin the overall efficiency and resilience […]
Development of the AASHTO Highway Safety Manual began from a TRB conference session and a workshop, both held in 1999, that identified the need for a traffic safety document analogous to the role of the Highway Capacity Manual for traffic operations. NCHRP Research Report 1140: Quantitative Safety Analyses for Highway Applications, from TRB’s National Cooperative Highway Research Program, describes […]
Bridge and tunnel strikes inflict serious damage to vehicles, highway bridges, and tunnels; cause injuries and fatalities; and impose detours and costly delays on highway users. Attempts by state departments of transportation (DOTs) and other bridge and tunnel owners to prevent bridge and tunnel strikes include signing, lighting, height detection systems, and actuated warning devices. […]