HOW TRAFFIC CALMING WORKS
What is Traffic Calming?
One of the historically reliable methods for traffic calming is vertical deflection, which adds a height variation to the road, causing motor vehicles to slow when approaching. Horizontal shifts and roadway narrowing are another way to implement calming measures. As with vertical deflection, traffic volume itself is relatively unaffected. These techniques will reduce vehicle speed and enhance streetscapes with minimal impact on traffic volume.
Traffic engineers, public works officials, and urban planners have many strategies for traffic calming including speed humps or tables, emergency-friendly speed cushions, lane narrowing, traffic circles, and improved bicycle access with designated bike lanes. These solutions are used to create more complete streets that offer safe access to all users.
Improving the streetscape will lead to a more walkable and bikeable area and allow for healthier lifestyles in the surrounding community.
Traffic calming has been shown to:
- Reduce speeding
- Improve speed limit compliance
- Decrease injury severity when crashes occur
- Lower fatality rates
- Encourage varied transportation modes
- Improve street aesthetics
- Increase property value
- Reduce crime
Does it work?
An FHWA study on speed reduction found that the 85th percentile speed was reduced by an average of 18% with speed humps, 19% with speed cushions, and 18% with speed tables.
Research abounds on the effectiveness of speed humps and other traffic calming methods in reducing speed and improving safety. The American Journal of Public Health found that children who live within a block of a speed hump have significantly lower odds of being struck by a vehicle. The Journal also found a 53-60% reduction in the odds of injury or death for children with traffic calming in their neighborhoods.
Slower cars save lives
Radar Sign Effectiveness
When cities use speed display signs they can expect to see reduction in average speeds, better speed limit compliance, and even long term reduction in speeding drivers and average speeds.
Here’s some sample data of the way speeds were affected after SafePace signs were installed on a local roadways.
Some studies that prove just how effective driver feedback signs are include:
•In South Dakota the percentage of speeding vehicles was reduced by 20-25%
•In Riverside, CA, drivers slowed by approximately 6 mph near speed trailer
•In South Korea, speeders were reduced from 27% to 10% with speed signs
•In Santa Barbara, CA average speeds were reduced by 10%
•In work zones, signs reduced the number of speeding truck drivers by 24%