After setting up illegal speed trap, this Arizona city is repaying drivers nearly $100K

The city had, more than a decade earlier, set up an illegal speed trap in front of Thompson Ranch Elementary School on Thompson Ranch Road north of Grand Avenue. Then, years later, the city installed photo enforcement cameras in front of the school. For a period of time from late 2016 to early 2017, the city issued citations on a stretch of the road where the speed limit dropped more than 10 mph, a violation of state law. ...

Crashes increase when speed limits dip far below engineering recommendation

Speed limits set only five miles per hour below engineering recommendations produce a statistically significant decrease in total, fatal and injury crashes, and property-damage-only crashes, according to a group of Penn State researchers. “If (however) you lower the speed limit by 10, 15, 25 miles per hour, or more, drivers stop paying attention,” said Vikash Gayah, assistant professor of civil engineering. “We found there was an increase in fatal and injury crashes at locations with posted speed limits set 10 miles per hour or more below engineering recommendations. ...