What is the “Pace” Method for Measuring Speed?

Posted Tuesday, October 27, 2020 by Andrew Charles Huff

A client asked me the other day about how police officers can measure the speed of a car without using a speed measuring device (SMD), commonly known as a radar or lidar. The question came about because she was recently pulled over by a Washington state trooper for speeding, but her speed was not measured by a radar gun. Instead. The trooper instead used the “pace” method to estimate speed.

First, there are three methods of estimating speed that is recognized by our state. One is the use of radar or lidar that most drivers are familiar with because we see officers standing on the side of the road pointing this device at passing traffic hoping for a high-speed reading. The second is the use of WSP aircraft to fly above traffic and, using pre-marked sections of the roadway, measure the speed of traffic by timing how long it takes cars to move from one pre-marked section to another.

So what is the “pace” method?

The ”pace” method allows an officer to measure the speed of another vehicle by maintaining an equal distance behind that vehicle and then use the patrol car speedometer to measure how fast the other car is traveling. In other words, if the other vehicle is traveling at and maintains an equal distance with the patrol car, then the patrol cars’ speed is the same speed as the other vehicle. The patrol vehicle’s speedometer to essentially used to measure another vehicle’s speed and must be proven accurate.