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Cannabis is the most widely used psychotropic substance surpassing alcohol use in 2022 in the United States. As with other impairing substances, evidence suggests that driving under the influence of cannabis is also associated with an increased risk of crashes, injuries, and fatalities. There is a paucity of evidence on strategies to impact driving after […]
With the recent liberalization of cannabis control laws, increasingly larger numbers of drivers are testing positive for cannabis. Research suggests many cannabis users believe driving under the influence of the drug is relatively safe. The purpose of this multiphase project was to understand cannabis users’ thoughts, perceptions, and reasons for driving under the influence of […]
The number of pedestrians killed on U.S. roads and streets has increased by more than 80% since reaching its modern-era record low in 2009. While the contributions of factors such as vehicle size and driver behavior have been the subject of extensive research, two additional factors also stand out: time of day and location. Virtually […]
This study explored the feasibility and acceptability of using stay in-place fiberglass reinforced plastic (FRP) jackets and underwater steel reinforced grout for timely bridge piling repairs in Minnesota without dewatering. One of the goals of the project was to determine the current state of practice to this corrosion repair and inspection by researching other projects […]
As separated on-street bicycle lanes become increasingly common, many state departments of transportation (DOTs) and local agencies have installed them to address safety concerns and promote cycling. Research was needed to provide state DOTs with detailed information on the anticipated safety benefits of bicycle network design features across various contexts, the relationship between these features, […]
GHSA’s analysis of preliminary data provided by State Highway Safety Offices (SHSOs) found that while pedestrian deaths during the first six months of 2024 fell slightly from the year before, they are 12% higher than 2019 and up a shocking 48% since 2014. Over the last decade, deaths of people on foot have risen at a pace […]
Roundabout implementation in the United States has increased in the last decade, and practitioners have learned lessons in successfully applying roundabouts in various land use and transportation environments and contexts. The TRB National Cooperative Highway Research Program’s NCHRP Research Report 1043: Guide for Roundabouts provides information and guidance on all aspects of roundabouts. Read the full guide […]
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 […]
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 […]