What is the proper speed limit in a residential area unless otherwise posted?

In Illinois, the standard speed limit in residential areas is established at 25 miles per hour unless otherwise indicated by signage. This speed limit is designed to enhance the safety of residents, particularly pedestrians, children playing, and cyclists, who may be present in these environments.

The rationale behind setting this limit at 25 mph is to reduce the likelihood and severity of accidents that can occur when vehicles travel at higher speeds in areas where people may be unexpectedly present on or near the roadway. This helps drivers have a better ability to react to sudden obstacles.

Setting lower limits, such as 20 mph or 15 mph, while effective for certain specific zones, isn't the general rule applied across all residential areas in Illinois. Maintaining a speed limit of 30 mph would not adequately address safety concerns specific to residential zones, where traffic is often mixed with non-motorized users. This standard encourages responsible driving behavior and fosters a safer environment for all residents.