Prevent fatal roadway crashes by standardizing the speed limit to 25 mph

“You can’t tackle our rising epidemic of roadway deaths without tackling speeding,” said NTSB Acting Chairman Robert L. Sumwalt. “Speed kills.” According to the U.S. Department of Transportation, in 2015 the percentage of fatalities involving speeding was higher on minor roads than on interstates and freeways. As we aspire to have safe streets for all users we can prevent traffic fatalities by establishing lower speed limits. The National Association of City Transportation Officials (NACTO) recommends street engineers bring street design in line with the target speed. Lower speed limits alone don’t reduce speeding, but as roads are resurfaced or updated, speed limits influence how they are designed, and give engineers the opportunity to design for the posted speed limit. (For example - narrowing lane widths, adding speed tables, or installing curb extensions lower speeds.)

Image Credit: PlanPhilly

The importance of reducing vehicle speeds is hard to dispute. Studies have shown that the risk of pedestrians or cyclists getting killed or injured escalates dramatically as the impact speeds reaches 30 miles per hour. Slower driving speeds significantly improve driver’s perception and reaction time, making it easier to avoid a crash and significantly changing the crash outcomes. Pedestrians have a 93% chance of surviving if they are struck by a vehicle traveling at 20 mph, while only 80% of pedestrians survive if the impact speed is 30 mph. A person is 70 percent more likely to die if they are hit by a car going 30 mph versus 25 mph. It is clear that slowing down cars even slightly can profoundly affect the difference between life and death.

Under the current City of Atlanta municipal code adopted in 1977, the city is divided into two speed zones. The maximum speed permitted in the inner zone -- defined as area within a radius of 2.5 miles centered on the intersection of Peachtree St. and Marietta St. -- is 25 mph. Meanwhile, the maximum speed permitted in the outer zone is 35 mph.

There is currently no standardized speed limit and any reductions of posted speed limits at 30 mph or less have been done on an ad hoc basis, wasting taxpayer dollars and delaying the safety benefits. 

Unlike cities like Austin and Boston, where bureaucratic obstacles challenged their ability to lower speed limits on neighborhood streets to 25 mph, Atlanta can standardize the speed limit. The State of Georgia has already given local governments more control of regulating traffic speeds on their streets. Georgia permits the alteration of speed limits within urban or residential districts to 25 mph.

In addition to promoting safer streets and improving public safety, reducing the speed limit to 25 mph can make more effective use of public funds. Rather than pay for the traffic studies required to propose a reduction of the posted speed limit for their streets, neighborhoods could request streetscape improvements.

The Atlanta Bicycle Coalition recommends that elected officials:

1. Request a study to evaluate the impact of a standardized speed limit of 25 mph.

2. Legislate a 25 mph speed limit on all streets within the City of Atlanta.

3. Support efforts at the state level to allow local governments to legislate 20 mph speed limit on local or residential streets.

4. Replace traffic signs as needed throughout the city.  

5. Launch a public education campaign to reinforce the message that speeding is both dangerous and illegal.

6. Ensure measurably equitable enforcement of the speed limits through use of automated speed cameras rather than traffic stops.