Speed Limits

Speed limit sign       Speed Limit FAQ 


Speed Limits

The City of Lake Forest has posted speed limits that range from 25 to 55 miles per hour. These speeds are based on traffic engineering surveys that consider the roadway conditions, accident records, and the speed of drivers. The maximum speed limit for any passenger vehicle is 55 miles per hour. All speed limits below 55 are either set by the Illinois Vehicle Code (e.g., 25 miles per hour in business or residential areas) or established through a traffic engineering survey.               

The speed limit is not always posted. But drivers are required to know to drive at a safe speed, as defined by the Illinois Vehicle Code. The speed limit is 25 miles per hour in the City of Lake Forest, unless otherwise posted. The City of Lake Forest must meet the standards of the Manual on Uniform Traffic Control Devices (MUTCD) to alter speed limits within the City.

A common perception is that posting a speed limit will influence drivers to drive at that speed. The facts indicate otherwise. National research has shown that drivers are influenced more by the appearance of the roadway itself and the prevailing traffic conditions than the posted speed limit.

Four widely held misconceptions about speed limits are:

  • Speed limit signs will slow down traffic.
  • Speed limit signs will decrease accidents and increase safety.
  • Raising a posted speed limit will increase the speed of traffic.
  • Lowering a posted speed limit will automatically decrease the speed of traffic.

Several studies have consistently shown t no significant changes in average vehicle speeds following the posting of new or revised speed limits. Similar research has found no direct relationship between posted speed limits and accident frequency.

Request for Speed Limit Changes 

The Traffic Safety Committee receives frequent requests for speed limit changes in various locations. These requests are evaluated after completion of a traffic engineering study that analyzes vehicle speeds, traffic volume, historical crash data from the specific location is analyzed and follows best practice guidelines outlined in the Manual on Uniform Traffic Control Devices (MUTCD).

How the Police Department addresses speeding cars? 

Many residents are faced with concerns about speeding on their local residential streets. In fact, speeding in residential neighborhoods is the biggest complaint given to police departments and city council representatives through the U.S.

Education - Most drivers who speed in neighborhoods actually live in the neighborhood. Increased patrols can help remind residents to drive the speed limit and set a good example for others.

Enforcement - The Police Department may respond with increased enforcement in neighborhoods where there are perceived traffic safety issues. When making complaints, residents should be specific regarding the days and times traffic issues occur to help determine when enforcement is needed.

Request a speed-monitoring trailer/radar sign -  These radar-equipped trailers or signs display the speed limit, show drivers how fast they are going, and act as temporary traffic calming devices.

Back to Traffic Safety Committee main page

Stay Informed!