NMA E-Newsletter #285: Can Pennsylvania Hold Out Much Longer?


Even though Pennsylvania scored in the bottom 10 in our recent rankings of how states treat drivers, motorists in the Keystone State can be happy about one thing: Pennsylvania is the only state in the country that prohibits local police forces from using electronic devices other than those that measure distance over time for speed enforcement. That privilege is reserved solely for the Pennsylvania State Police.

The state legislature adopted the ban in 1961 to discourage the proliferation of speed traps. It appears to have succeeded. Based on data from the NMA’s www.speedtrap.org, out of the top 200 cities ranked by number of speed traps, Pennsylvania only has two on the list. In contrast, Florida and California both have 25, Texas has 23, and Ontario, Canada, has 22.

That may change as the state legislature once again considers a bill to allow local police to use radar and lidar. (Both technologies have weakness that can be challenged.) Similar bills have been introduced many times previously, and all have failed. But things seem different this time. The current bill appears to have more support; it’s certainly getting much more attention from the press and the public, based on the volume of media inquiries we’re receiving. We’ve responded by saying that Pennsylvania should stick to its guns. (But not its radar or lidar guns.)  Here’s why.

Radar does encourage the widespread operation of speed traps. That’s why the ban was passed in the first place. Speed traps are designed to target motorists by taking advantage of artificially low speed limits coupled with high traffic volume. Adding radar simply allows the police to prey on a larger number of responsible drivers, with no measurable benefit to highway safety. If safety were the goal, policymakers would mandate the proper setting of speed limits according to the 85th percentile standard, which would reduce accident rates and eliminate speed traps.

Radar has an air of infallibility, but in reality, it’s subject to a host of errors making it unreliable for speed enforcement. Most significantly, it cannot distinguish a specific vehicle among a group of vehicles. How can the officer know for sure he’s targeting the right one? Contrast this with other speed detection methods used in Pennsylvania like VASCAR and ENRADD that clock one vehicle at a time.

In addition, a wide range of factors can interfere with the radar signal and create incorrect readings. Some of these include power lines, electric substations, trees, bad weather, operator error and even the heater fan inside the police cruiser. So much for infallibility.

Radar units must receive routine maintenance and calibration to function properly, and officers must be trained to use the units correctly. Despite what a police officer says on the witness stand, these important requirements are not always met.

The pending Pennsylvania legislation provides no mechanisms to limit any of the radar misuses and abuses described above. If radar use does spread to local police, it will come with little oversight or accountability. This is the case in many states, unfortunately.

A better legislative model comes from California Vehicle Code, Section 40802, known as the “speed trap law.” The law prohibits police from using radar/laser speed detection on any road that hasn’t had a valid speed study completed within a given period of time, usually five years. It also mandates requirements for instrument calibration and officer training/certification. (Note, this law does not apply to interstate highways.)

Is California’s law perfect? No. But it does represent an honest attempt to control for the abuses radar use engenders. A few other states, like Georgia, have speed trap laws of their own. Others, like Massachusetts, have adopted standards that define illegal or unreasonable speed limits.

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