What are “special conditions” speed limits?

You are probably familiar with the posted speed limits that you see on Illinois streets and highways. You may also be aware of statutory speed limits. The state legislature sets these to apply where there are no posted speed limits.

Special conditions speed limits are more important than posted or statutory limits. There are three different types of special conditions speed limits. You need to be aware of where you might encounter them.

Variable speed limits

Variable speed limits go into effect when there is a temporary issue that requires slower speeds. Traffic accidents and bad weather are conditions that may require variable speed limits. You may see a changeable message sign informing you of the situation and the variable speed limit.

School zone speed limits

Children do not always pay attention to traffic when walking to and from school. Therefore, you may see slower speed limits in school zones. If a child runs into the road, a slower speed gives you time to stop. According to the Federal Highway Administration, speed limits in school zones are typically between 15 to 25 miles per hour.

Work zone speed limits

Road construction can mean hazards such as two-lane traffic or heavy equipment. To keep traffic moving safely and efficiently through work zones, you may have to observe a slower speed limit than usual.

Some special conditions speed limits, such as variable speed limits and work zone speed limits, are only temporary. School zone speed limits are permanent. However, look carefully at the signs. Sometimes they say things like “when children are present” or “when lights are flashing.”