What Is the Speed Limit in a Construction Zone If Not Posted?

June 11, 2024

Speeding in construction zones in Illinois is taken very seriously due to the high risk it poses for both workers and motorists. The legal framework, penalties, and enforcement measures are designed to ensure maximum safety in these zones. Below, we break down the key aspects and ramifications of speeding in construction zones in Illinois.

Legal Framework

"Speed limit and person-digging signs for freeway construction" by Eric Fischer is licensed under CC BY 2.0. To view a copy of this license, visit https://creativecommons.org/licenses/by/2.0/.

Illinois Law (625 ILCS 5/11-605.1)

The legal basis prohibiting speeding in construction or maintenance zones in Illinois is detailed in Illinois Law (625 ILCS 5/11-605.1). This statute mandates that construction or maintenance zones must be officially designated by a governmental authority and must include proper signage indicating the speed limit and fines.

Designation and Signage Requirements

A construction or maintenance zone must meet specific designation and signage requirements. Proper signage must clearly indicate the speed limit and the fines for violations to ensure that motorists are well-informed when entering a construction zone.

Scope of the Law

Applicability Regardless of Workers’ Presence

The law applies regardless of whether workers are present to protect both workers and motorists. Construction zones often have potential hazards like equipment, narrow lanes, lane shifts, and barriers that can be dangerous, which makes adherence to reduced speed limits crucial.


Statistics show that 90% of injuries or deaths in construction zones involve motorists, not workers, underscoring the importance of following speed limits in these areas.

Penalties for Violations

"Speed Limit Construction" by fullcirclepiece is licensed under CC BY-NC-ND 2.0. To view a copy of this license, visit https://creativecommons.org/licenses/by-nc-nd/2.0/.

First Violation

First-time offenders face a fine ranging from $250 to $1,000. This steep fine aims to deter motorists from speeding in construction zones.

Subsequent Violations

A second or subsequent speeding offense incurs a higher minimum fine of $750. Additionally, a second or subsequent violation within two years results in a 90-day driver's license suspension, particularly if workers were present during any of the offenses.

Aggravated Offenses

Excessive Speeding

For more severe cases, such as speeding 26 to 34 miles per hour over the limit, the offense is classified as a Class B misdemeanor, punishable by up to 6 months in jail and a $1,500 fine. For those speeding 35 miles per hour or more over the limit, it becomes a Class A misdemeanor, punishable by up to one year in jail and a $2,500 fine.

Automated Enforcement

Automated Traffic Control Systems

Illinois uses automated traffic control systems, like photo-enforced speed detection devices, in construction zones. These systems capture photographic evidence of speeding violations and send tickets by mail. The systems must adhere to specific legal guidelines to ensure accuracy and fair enforcement.

Legal Defense

Role of Traffic Attorneys

Given the severe penalties for speeding in construction zones, it is crucial to have an experienced traffic attorney to navigate the complexities of the legal system. An attorney can help challenge the evidence, question the proper use of photo enforcement systems, and provide a robust defense.

Potential Defenses

Possible defenses a lawyer might use include questioning the accuracy of the speed detection equipment, improper signage, or the actual designation of the construction zone. These factors can make a significant difference in the outcome of a case.

Practical Advice

If you face charges for speeding in a construction zone, consulting with a specialized traffic lawyer is highly recommended. Legal representation can help mitigate penalties and navigate the intricacies of traffic law to provide the best possible outcome.

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