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Culverts are buried drainage structures underneath roadways or embankments that are open at both ends and used to convey and transport water. They can often be vulnerable to accelerated deterioration when there is more frequent severe weather, which can lead to a suite of costly unplanned repairs, rehabilitation projects, or full replacements. NCHRP Synthesis 651: […]
Severe weather events can impact transit agency operations, equipment, and infrastructure. For example, Hurricane Katrina in 2005 destroyed the transit fleet of the New Orleans Regional Transit Authority, more than 300 buses. In another example, an EF-4 tornado in 2021 destroyed the fleet of the Fulton County Transit Authority in Kentucky. TCRP Synthesis 180: Transit […]
Drivers are considered to be alcohol-impaired when their blood alcohol concentrations (BACs) are .08 grams per deciliter (g/dL) or higher. Thus, anyfatal traffic crash involving a driver with a BAC of .08 g/dL or higher is considered to be an alcohol-impaired-driving crash, and fatalities occurring inthose crashes are considered to be alcohol-impaired-driving fatalities. The term […]
The National Highway Traffic Safety Administration considers a traffic crash to be speeding-related if any driver in the crash was charged with a speeding-related offense or if a police officer indicated that racing, driving too fast for conditions, or exceeding the posted speed limit was a contributing factor in the crash. A speeding-related fatality is […]
Emerging technologies present many potential challenges to state departments of transportation (DOTs) and other agencies that own and manage the existing infrastructure. Significant uncertainty exists about which changes are most likely to occur and where the largest impacts could be, hampering an effective national alignment in policy and approach. NCHRP Research Report 1090: Risks Related […]
The high-voltage battery pack of an electric vehicle is often the main weapon of choice for people who have never driven an EV but like to discredit the technology. “It won’t last more than a couple of years” is a sentence that I’ve heard time and time again when talking to gas car enthusiasts about […]
Traffic control devices, markings, signals, guardrail, computing systems, communications infrastructure, and other permanent and temporary devices will likely each be affected by the operation of connected and autonomous vehicle (CAV) technology. State departments of transportation (DOTs) need to identify gaps in knowledge and skills and prepare for the challenges of CAV implementation while maintaining the […]
Traffic control devices, markings, signals, guardrail, computing systems, communications infrastructure, and other permanent and temporary devices will likely each be affected by the operation of connected and autonomous vehicle (CAV) technology. State departments of transportation (DOTs) need to identify gaps in knowledge and skills and prepare for the challenges of CAV implementation while maintaining the […]
Generative Artificial Intelligence (AI) is redefining how people interact with public information and shaping how public data are consumed. Recent advances in large language models (LLMs) mean that more Americans are getting answers from AI chatbots and other AI systems, which increasingly draw on public datasets. The federal statistical community can take action to advance […]
Cars, trucks, and other vehicles can emit air pollutants harmful to human health. CMAQ supports projects in areas that do not currently, or did not in the past, meet federal air quality standards for certain air pollutants—carbon monoxide, ozone, or particulate matter. The Infrastructure Investment and Jobs Act provided about $2.7 billion for CMAQ in […]