Systems Planning

Idle Free Ann Arbor

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On July 1, 2017, a new idling ordinance (PDF) will go into effect in Ann Arbor.


  • Commercial vehicles: 5 minute idling limit city-wide and no idling while vehicles are unoccupied.
  • Non-commercial vehicles: 5 minute idling limit in signed "No Idling" zones and no idling while vehicles are unoccupied. 
*The ordinance does not impact cars on residential property or in driveways. 

Do Your Part

1. Turn your engine off.  Whether you're picking up your child from school or using the ATM, turn off your engine if you're stopped for longer than ten seconds.

2. Reduce warm-up idling. Experts agree modern engines require only a short idle period after engine start—even in very cold temperatures. Driving slowly for the first mile or two is the best way for the car to warm up.  Long idling periods can harm your engine and waste gas.

3. Spread the word.  Most people idle out of habit.  Encourage your family, friends and neighbors to help protect children's health, the environment, and save money by turning off their vehicles. 

Idling Quiz

For a fun, easy way to test your idling knowledge, take Washtenaw County's 10-question online quiz.

Myths and Facts


  • Vehicle idling constitutes 1.6% of all U.S. greenhouse gas emissions, double the total emissions from the steel and iron manufacturing in the country.
  • Idling for 10 seconds uses more fuel and emits more CO2 than restarting your vehicle. 
  • Newer, gas powered vehicles don't need to idle when it's cold out. Most synthetic oils will flow at temperatures well below 0. 
  • Warming up a diesel engine in winter, in a truck for example, needs no more than 30 seconds. Driving cuts warm-up time in half and is easier on the engine than idling.