What is the 85th percentile speed?
The 85th percentile speed is the speed at which 85 percent of the vehicles are traveling at or below. This is not the average speed. We use the 85th percentile speed to set the speed limit.

Arbitrarily setting a residential speed limit below the 85th percentile speed is not an effective policy for increasing traffic safety. Reasonable drivers can start to ignore the posted limit, leading to a broader disregard for speed limits in general. This in turn burdens law enforcement officials with ticketing otherwise reasonable drivers in addition to those who are truly posing a danger to public safety. Furthermore, areas like school zones that may legitimately require a speed limit below the 85th percentile will see a decreased benefit when adjacent streets are posted with an unreasonably low speed limit.

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1. What can I do if there is a speeding problem in my neighborhood?
2. Can Lowering the Speed Limit Solve a Speeding Problem?
3. What is the 85th percentile speed?
4. How do I get a streetlight installed on my street?
5. How do I get "Children At Play" signs installed on my street?
6. Why do some of the school zones have flashers?
7. When are the school zones operational?
8. How can we get a school crossing guard?
9. What do the Walk / Don't Walk signals mean?
10. How can we get stop signs installed along our street?
11. How do we get a multi-way stop?
12. How can we get a traffic signal installed?
13. How are design engineers and Materials Testing firms selected for city projects?
14. How are general contractors selected for city projects?