The Crittenden Automotive Library

Woodstock's Radar Trailer

Woodstock's Radar Trailer

Gus Philpott
Woodstock Advocate
March 20, 2008

Radar!

What do you think or feel when you see or hear that word? With reference to driving your automobile, I mean? Fear? Panic? Do you immediately check your speedometer? Do you know what the posted speed limit is where you are?

Have you ever been stopped by a traffic officer who informed you that your speed had just been checked (clocked?) by radar? Have you received a ticket by mail for speeding in an Illinois highway work zone? Was your assumption that the radar was accurate?

And when you see a radar speed trailer sitting on the side of the road, what are your thoughts?

I used to think that the radar trailer was there to remind me of the speed limit AND to help me determine whether or not my vehicle's speedometer was accurate; i.e., if my speedometer indicates 30MPH, am I really traveling at 30MPH?

Then one day I asked several area law enforcement agencies whether their radar speed trailers were accurate. Not one agency told me that its radar display on the trailer was accurate! By "accurate", I mean exact, correct, a true reading.

All replied that the speed displayed was close to the speed of the moving vehicle passing through. "Could be 2-3 MPH off" was the usual answer. There seemed to be several reasons for the inaccuracy: not calibrated for true speed in the first place; age of equipment; maintenance of the equipment; weather.

So, if you use a radar speed trailer to "measure" your speed and determine how accurate your speedometer is, DON'T. Don't rely on it. Yes, it will be "close" and, if you think that is good enough to keep you out of hot water with an Illinois Work Zone photoradar unit and a police officer's radar unit in his vehicle, then at least you know your car's speedometer might be off.

Years ago radar officers were supposed to calibrate their radar units on a daily basis; maybe even after each ticket, depending on the department and its requirements. And the unit was to be used in accordance with the instruction manual.

I knew one deputy in Colorado who liked to hold the unit inside the car and aim it into the outside rearview mirror on the driver's door. This kept the unit out of the view of an approaching driver who might be looking for the unit's being mounted on the outside of the left rear door window. The instruction manual specifically said not to operate it that way, but that did not phase her in the least. She knew that most drivers would just pay the ticket and, if a case did go to court, the driver or his attorney might fail to ask if the radar gun was operated in accordance with the instruction manual.

Are there streets in Woodstock where you would like the radar speed trailer used? Send an email to speedtrailer@woodstockil.gov and let them know where you would like it.

Locations I have suggested are:

Southbound Route 47, south of US 14

Northbound Route 47, in front of Kmart

Eastbound US 14 by Culver's

East- and westbound Lake Avenue in front of Wal-Mart

Where would you like to see it used? Post your suggestions here.