UNIT 2: ROADWAY SAFETY
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Enabling safer vehicles also means employing strategies to improve the safety of the commercial motor vehicles that transport goods and carry thousands of passengers locally and across the country every day.
The data visualization below focuses on large truck safety.
Through the NRSS, the Department will continue to leverage enhanced motor vehicle safety performance and technologies to improve safety for vehicle occupants and other road users, too.
Key Departmental Actions to Enable Safer Vehicles
Safer Speeds
Promote safer speeds in all roadway environments through a combination of thoughtful, equitable, context-appropriate roadway design, targeted education, outreach campaigns, and enforcement.The Department believes it is important to prioritize safety and moving individuals at safe speeds. Both exceeding the posted speed limit and driving too fast for conditions are speeding-related crash factors.
The Effects of Speed on Roadway Fatalities
Speeding increases both the frequency and severity of crashes, yet it is both persistent and largely accepted as the norm amongst the traveling public. Unsafe speeds are a well-documented and understood factor in death and injury, especially among people outside of a vehicle. Managing speeds and addressing issues of speeding will improve safety.
Impact Speed and a Pedestrian’s Risk of Death
Speeding is a significant contributor to deaths on our roadways and is particularly hazardous to pedestrians. Yet, speeding remains worryingly common.
The relationship between impact speed and a pedestrian’s risk of death has been studied extensively; however, past studies of data from the United States are now several decades old. Older studies of data from the United States may not be generalizable to the present situation because of changes in the composition of the walking population, vehicle design, and medical care over the past several decades. Similarly, the ability to generalize from recent European studies to the United States is unclear due to differences in the types and sizes of vehicles driven in Europe versus in the United States.
This study estimates of the risk of severe injury or death for pedestrians struck by vehicles in the United States using data from a federal study of crashes that occurred in the United States in years 1994 – 1998 in which a pedestrian was struck by a forward‐moving car, light truck, van, or sport utility vehicle. The data were weighted to correct for oversampling of pedestrians who were severely injured or killed. Logistic regression was used to adjust for potential confounding related to pedestrian and vehicle characteristics. Risks were standardized to represent the average risk for a pedestrian struck by a car or light truck in the United States in years 2007 – 2009.
Results show that the average risk of severe injury for a pedestrian struck by a vehicle reaches 10% at an impact speed of 16 mph, 25% at 23 mph, 50% at 31 mph, 75% at 39 mph, and 90% at 46 mph. The average risk of death for a pedestrian reaches 10% at an impact speed of 23 mph, 25% at 32 mph, 50% at 42 mph, 75% at 50 mph, and 90% at 58 mph. Risks vary significantly by age. For example, the average risk of severe injury or death for a 70-year-old pedestrian struck by a car traveling at 25 mph is similar to the risk for a 30‐year‐old pedestrian struck at 35 mph.
These results could be used to inform efforts to improve pedestrian safety, for example, by limiting traffic speeds to levels that are unlikely to result in severe injury or death in places where pedestrians and vehicles may encounter one another, creating physical separation of pedestrians and vehicles in places where higher traffic speeds are desired, and developing vehicle‐based systems that detect pedestrians and warn the driver or brake automatically when a collision is imminent.
Sources: Fatality Analysis Reporting System; Early Estimates of Motor Vehicle Traffic Fatalities and Fatality Rate by Sub-Categories in 2020, DOT HS 813 118, June 2021; AAA Foundation for Traffic Safety, National Traffic Speeds Survey III: 2015, DOT HS 812 485, March 2018.
Speeding-Related Fatalities
The data visualization below provides a tool to better understand the impacts of speeding-related crashes on roadway fatalities.
Achieving Safe Speeds
In alignment with the Safe System Approach, achieving safe speeds requires a multifaceted, equitable approach that leverages road design and other infrastructure interventions, education, and enforcement.
Appropriate Speed Limits for All Road Users
There is broad consensus among global roadway safety experts that speed control is one of the most important methods for reducing fatalities and serious injuries. Speed is an especially important factor on non-limited access roadways where vehicles and vulnerable road users mix.
A driver may not see or be aware of the conditions within a corridor, and may drive at a speed that feels reasonable for themselves but may not be for all users of the system, especially vulnerable road users, including children and seniors. A driver traveling at 30 miles per hour who hits a pedestrian has a 45 percent chance of killing or seriously injuring them. At 20 miles per hour, that percentage drops to 5 percent. A number of cities across the United States, including New York, Washington, Seattle and Minneapolis, have reduced their local speed limits in recent years in an effort to reduce fatalities and serious injuries, with most having to secure State legislative authorization to do so.
States and local jurisdictions should set appropriate speed limits to reduce the significant risks drivers impose on others-especially vulnerable road users-and on themselves. Addressing speed is fundamental to the Safe System Approach to making streets safer, and a growing body of research shows that speed limit changes alone can lead to measurable declines in speeds and crashes.