Archive · 18 Aug 2025
US States Reconsider Speed Limits: Safety vs. Driver Speed
Some states are rethinking how they set speed limits on roads.
For a long time, they used a rule called the 85% rule, which means they set the speed limit based on how fast most cars drive.
However, this rule is old and doesn't always make roads safe.
Now, states are starting to consider other things, like how many people walk or bike on the road.
Some people want to lower speed limits to make roads safer for everyone, while others believe setting speed limits according to traffic flow is the best approach.
The goal is to reduce accidents and make roads safer.
US states are re-evaluating the practice of setting speed limits based on how fast drivers travel.
The 85% rule, which ties speed limits to the speed most vehicles travel, is being questioned due to outdated research.
Some states are modifying speed limit guidelines to consider factors like road use and pedestrian safety.
Advocates for safety want to reduce the influence of the 85% rule and prioritize all road users.
Studies show increasing speed limits can increase fatalities, and some cities are lowering limits to improve safety.
- Who
- State officials, engineers, safety advocates, and drivers are involved.
- What
- US states are reconsidering speed limit practices.
- When
- The shift away from the 85% rule is ongoing, with some states already changing guidelines.
- Where
- Across the US, with examples in Ohio, Wisconsin, California, and Seattle.
- Why
- Due to outdated research, rising road deaths, and a desire to prioritize safety.
Safety Advocates
Driver Advocates
Road User Safety
Safety Advocates
Prioritize the safety of all road users.
Driver Advocates
Prioritize automobile traffic flow.
Speed Limits
Safety Advocates
Favor lower speed limits.
Driver Advocates
Favor speed limits reflecting driver behavior.
- 85% Rule
- Links speed limits to the speed most vehicles travel.
- Federal Guidelines
- The Federal Highway Administration updated its manual for traffic signs in 2024.
- Speed Limit Increase Risk
- A 5 mph increase in speed limits increases fatalities.
- Wisconsin Example
- Madison is lowering residential speed limits to 20 mph.
- California Example
- California allows departures from the 85% rule when safety needs are proven.