How Traffic Calming Works

HOW TRAFFIC CALMING WORKS

What is Traffic Calming?

Traffic calming is the use of physical solutions to reduce traffic speeds and/or cut-through traffic with the goal of making streets safer and more accessible for motorists, bicyclists, and pedestrians. It has been proven as an effective way to reduce speeding on residential streets, avoid traffic crashes, and prevent needless fatalities.

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.

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

While solutions can be instituted at the street, neighborhood, or city-wide level, traffic calming is most effective when it is part of a proactive program to improve street safety based on highest need. This is often ascertained with a points program to determine where risk is highest.

Does it work?

Does traffic calming really slow cars down? Study after study has reached the same conclusion. Traffic calming solutions improve safety, reduce speeds, and prevent crashes every day.

An FHWA study on speed reduction found that the 85^th 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

Does slowing cars just a few miles an hour really make a difference? View the survival chance (%) of pedestrians when a vehicle is travelling at the following speeds:

Vehicle Travelling at 20 mph 90%

Vehicle Travelling at 30 mph 50%

Vehicle Travelling at 40 mph 10%

Speed Humps
Speed Cushions
Speed Tables

Radar Sign Effectiveness

They’re easy to install, brightly lit, and can flash at drivers who speed. But do they work? In short, yes. Radar speed signs really do slow cars down. And slower cars have been proven to reduce accidents and decrease impact when accidents happen.

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:

A landmark study from Bellevue, WA which concluded that “At the majority of radar sign locations, results show an overall reduction of vehicle speeds between 1 and 6 mph, even up to 8 years after the signs were installed. Due to this level of effectiveness, the City will continue to use stationary radar signs….. to address vehicles speeds and/or….. motorist’s attention…..”

A report on speed sign effectiveness compiled by the Western Transportation Institute on behalf of the US DOT and the State of California found that:

•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%

An evaluation by the Texas Transportation Institute of speed display trailer use in work zones found that the signs reduced average speeds by around 5 mph and were well liked by construction workers who felt that they “increased awareness of the work zone and significantly lowered speeds in the activity area.”

A study by the Texas Transportation Institute found that driver feedback signs “significantly reduced vehicle speeds at a school zone.…the average speed decreased more than 9 mph… [even] four months after installation.”

Research quoted in Wired Magazine found that radar speed signs “have proven to be consistently effective at getting drivers to slow down- reducing speeds by about 10%, an effect that lasts for several miles down the road.”

A study conducted by the Maryland State Highway Administration of speed signs in work zones found that the display trailers reduced average speeds by 2-7 mph and increased speed limit compliance by 10-40%.

Want to read more about how SafePace signs will change the way people drive on your streets? Take a look at some success stories here.

View Success Stories

Some eye-opening traffic calming statistics:

More than half of road accidents in India are caused by speeding drivers.

Close to 1,250,000 people die each year around the world because of road traffic crashes.

90% of the world’s fatalities on the roads occur in low- and middle-income countries, despite the fact that these countries only house around half of the world’s vehicles.

Around 50% of traffic related deaths are to “vulnerable road users”: pedestrians, cyclists and motorcyclists while traffic injuries are the leading cause of death among young people aged 15-29 years.

Without action, road traffic crashes are predicted to become the 7th leading cause of death across the world by 2030.

77% of accidents in India are the fault of the driver.

Road accidents don’t only affect personal lives; they are estimated to reduce India’s GDP by 3% each year.