There’s a clear connection between vehicle speeds and safety on the road. The faster a vehicle moves, the more dangerous crashes become. This is especially true for crashes involving pedestrians. The National Highway Traffic Safety Administration (NHTSA) found that when a pedestrian is struck by a vehicle traveling 40 MPH, they have an 80% chance of serious injury or death. But when a pedestrian is struck by a vehicle traveling 20 MPH, they only have a 10% chance of serious injury or death.
NHTSA reports that speeding is a factor in nearly one-third of all traffic fatalities in the United States. When a driver is moving fast, they have less time to react to unexpected situations, such as a pedestrian crossing the street or a car suddenly stopping ahead. And when crashes do occur, higher speeds increase the likelihood of serious injuries or fatalities.
Design for a safe system
Reading the stats about vehicle speed, one obvious question is “are these tragedies preventable?” The answer is a resounding “Yes.”
Streets are either designed for safe behavior or reckless behavior.
Lower speeds on downtown and neighborhood streets improve safety for everyone. Fewer crashes, fewer injuries, and fewer fatalities. This is part of what makes a place livable, not only for motorists but also for pedestrians, cyclists, and people waiting for the bus. The only way to do this is by thinking beyond the curbs. The entire mobility system plays a big role in the overall design of the built environment, and while that may sound obvious, it’s not a high priority consideration among conventional professionals when thinking about traffic safety.
The "safe systems" approach to transportation safety and urban design is evidence-based, which refers to an approach that relies on empirical data and research to inform decisions. It’s designing an urban environment according to what has been demonstrated to have improved other urban environments.
We use a variety of methods to gather and analyze data, including surveys, interviews, observations (see William Holly White), and statistical analysis, to understand what will work best for a particular community. Two important principles of safe systems are (1) safe roads/roadsides and (2) safe speeds. It’s no mistake that such heavy emphasis is placed on vehicular traffic to make life better for everyone.
Lower speeds on downtown and neighborhood streets improve safety for everyone. Fewer crashes, fewer injuries, and fewer fatalities. This is part of what makes a place livable, not only for motorists but also for pedestrians, cyclists, and people waiting for the bus. The only way to do this is by thinking beyond the curbs. The entire mobility system plays a big role in the overall design of the built environment, and while that may sound obvious, it’s not a high priority consideration among conventional professionals when thinking about traffic safety.
The "safe systems" approach to transportation safety and urban design is evidence-based, which refers to an approach that relies on empirical data and research to inform decisions. It’s designing an urban environment according to what has been demonstrated to have improved other urban environments.
We use a variety of methods to gather and analyze data, including surveys, interviews, observations (see William Holly White), and statistical analysis, to understand what will work best for a particular community. Two important principles of safe systems are (1) safe roads/roadsides and (2) safe speeds. It’s no mistake that such heavy emphasis is placed on vehicular traffic to make life better for everyone.
People who are walking, biking, or waiting for public transit can find car traffic to be a real nuisance or even dangerous for several reasons:
Noise: Prolonged exposure to traffic noise can cause stress, hearing damage, and other health problems.
Air Pollution: Breathing in car exhaust can lead to respiratory problems, heart disease, and other health issues.
Safety: Drivers don’t always see or react in time to people walking or riding their bikes, especially when streets are designed for high speeds with little to no consideration of other street users..
Accessibility: Busy streets can be intimidating or even impossible to cross, especially for people with mobility or visual impairments.
Stress: The noise, pollution, and safety concerns can all contribute to a sense of anxiety or unease.
Practical design tips
When you think holistically about the built environment, experts naturally come back to needing design techniques to encourage safe driving behaviors. Remember that physical design can create a street environment that conveys the message that slow and careful driving is expected and appropriate.
Here are some proven techniques that have positive cognitive impacts on drivers:
Narrower lanes: Wide lanes can give drivers a false sense of security and encourage them to drive at higher speeds. By narrowing lanes, drivers get a visual cue to slow down and pay closer attention to their surroundings.
Traffic calming measures: Speed humps, bulbouts (curb extensions) or chokers, chicanes, raised crosswalks, and roundabouts have become more common because of their safety benefits.
Visual cues: Pavement markings, brightly colored crosswalks, textured surfaces, and landscaping can make the street environment more engaging and help communicate that the street is designed for people, not just vehicles.
Intersection design: Generally speaking, smaller intersections are safer intersections. Also, designing with tight turning radii and curb extensions shortens crossing distances for pedestrians at the same time drivers are moving much slower. Roundabouts are an increasingly popular intersection design alternative for streets with lower traffic volumes.
Policy supporting design
Policy is also an important strategy for a safe systems approach. Prioritizing walking, bicycling, and public transit over single-occupancy vehicle travel means that car infrastructure shouldn’t dominate the infrastructure budgets.
It takes political will, but your community can absolutely develop safe, accessible, and efficient alternatives to accommodate a wider range of travel modes while mitigating the negative impacts of vehicle speeds.