Concerning pending legislation to increase Illinois speed limits and a compromise that may leave final decisions to the counties, limits should be increased statewide, including most Chicago-area expressways.
Studies have long shown that speed limits have little effect on the pace of faster traffic, and any traffic engineer will explain that 85th percentile speeds are the proper way to set limits (the maximum speed at which 85 percent of traffic actually flows when unencumbered).
Unreasonably low limits do not slow down faster traffic but do cause several types of dysfunction which make the roads more dangerous, including:
• Increased road rage. This is brought on by the points noted below.
• Increased speed variance. Slower traffic tends to flow at the posted limit thus increasing speed variance between the fastest and slowest traffic -- a leading cause of road rage when drivers do not keep right and yield to faster traffic.
• Distracted/impaired drivers. Dumbed-down limits encourage distracting activities like texting and contribute to road rage when drivers are too busy to notice someone wants to pass.
• Increased congestion. Heavy traffic can only move as fast as the slowest car. Lower limits increase gridlock.
• Punitive speeding penalties. Illinois instituted "super-speeder laws" recently. Under this law a person can go to jail for driving 85 mph in the Chicago area (30 mph over the limit). If enforced our prisons would soon be full.
• Loss of respect for all traffic laws. When limits are set at 55 on expressways, some will learn to disregard limits on roadways where 55 is an appropriate speed -- including construction zones.
In addition, insurers, including AAA, like low limits and speed traps because these enable them to charge safe drivers higher rates without any additional risk.
Former coordinator, Illinois State Chapter
National Motorists Association