Saturday, April 25, 2015

Photo Radar Insanity

Pima County announced yesterday that it is considering adding up to 12 additional photo-radar sites. From the article, it appears that the criteria for adding the sites is this:  They will be inexpensive to install.  Boy does this get my blood boiling.

You see, Photo Radar can be expensive to install because it requires underground conduit.  But it is much cheaper to install when a roadway is being ripped up for another construction project.  From what I tell, this is why these locations are being chosen for Photo Radar – It will be inexpensive to install because of other construction along the roadway.

But I have two problems with this.  First, is the concept of photo-radar altogether.  As near as I can tell -they are almost always installed at speed traps.  What is a speed trap?  Let me explain.

A speed limit is a posted speed along a roadway that creates a prima-facie evidence that you are driving recklessly.  Before speed limits were introduced, a police officer had to prove that the motorist’s rate of speed was reckless.  This could be very difficult.  So to facilitate this, traffic engineers conducted speed studies along all the roadways within their jurisdiction.

The general principle is this:  Most people will drive at a safe rate of speed.  So the traffic engineer would determine the rate of speed at which 85% of drivers would not exceed. This was done by measuring the speed of every vehicle along the roadway.  Then, the engineer would round this up to the next highest 5 mph.  So if 85% of the people were driving 42 miles per hour, the speed limit would typically be set at 45 miles per hour.

This system really worked well.  If the speed limit was set at 45 miles per hour, and someone was driving 60, he was obviously being reckless and warranted a ticket.

The problem comes when a speed study is not done.  In many instances now, the speed is simply set by someone estimating what a proper speed should be.  Here in Vail, we have a road, Mary Ann Cleveland Way.  This is a two-lane road that goes through 4 miles of wilderness.  Now there are bike lanes along the side of the road (That deserves another post) and so the risk of an accident with a bicycle is real.  But the road is posted at 45 miles per hour.  When you drive the roadway, it is almost impossible to drive 45 miles per hour.  In fact, I have to set my cruise control to make sure I don’t speed.  If the County were to perform a speed study, I’m sure the speed limit would be set at 65 miles per hour.  So, when people drive what comes naturally to them, they are “speeding”.  If Pima County wants to give out a lot of tickets, Mary Ann Cleveland Way is a place to do it.  It is a speed trap.

As I have observed the location of permanent photo-radar locations, in every instance they have been placed along speed traps.  So they really serve no other purpose than raising money for the County.

But secondly,  if you are going to place photo-radar at all, they should be based on a better criteria – say accident rates. The County could review accident rates along all of the major roadways and find locations where accidents are high due to speed.  This does happen sometimes...  If there is a blind curve or a poor sight distance.  The County may not have money to fix these locations – so a photo-radar system may actually be of benefit.

But according to the news article, the location of the proposed photo-radar is not based on accident locations.  It isn’t based on anything other than the fact that it will be cheap to install.

That is not right.  Because rather than adding photo-radar to decrease accidents, they are being considered for economic gain.