Do you know how fast you were going?

Yes, but how did they?

Speed detection is one of the  most  notorious functions of our local and state police.  How do they know how fast we are going?

Speed determination is accomplished in two basic ways.  First, the least sophisticated method is dependent upon an officer's ability to guess your speed.  Second, either some electronic method using  radar or laser instrumentation  authenticates that officer's guess.  As you will see, their guesses are usually right on target.

What does this mean for you?  Usually a speeding ticket or if your infraction isn't a flagrant disregard for safety, a friendly warning.


Homepage | Basic Theory | Manual Speed Detection | Radar Speed Detection | Laser Speed Detection | The Doppler Effect | Directory of Related Links | Bibliography


Kim Phillips
Physics 211
Dr. David Newman
11/27/02