How did police estimate MPH before there was radar ?

Question

I think it had something to do with the number of seconds it took the vehicle to go from one telephone pole to the next.

Answer 1

Yeah it was something like that - even now you see the white lines going across the road...they can judge how fast youre going by how long it takes to go from 1 line to the next.

Answer 2

The California Highway Patrol still doesn't use radar, until the specific county they work in pays for them. They are taught how to estimate speed, and they are good enough to be accepted as evidence in court. I remember once while sitting in a truck stop watching a a traveler from Texas being pulled over on Highway 99. Immediately, he began raising all kinds of hell over the fact that he had all these different types of radar suppression devices in his car, yet he still got pulled over by the CHP for speeding. The officer just stood there until he was done ranting, then informed him that they didn't use radar units.

Answer 3

there are all kinds of fixed distance markers (mile markers, telephone polls, road markings. The subjective part (which made is so easy to beat) was that the observer could never be accurate about your crossing either marker over a signifigant distance. If the distance between his measurements was too short, then the accuracy of his timing could be questioned. If the distance was too great - how did he determine when you actually crossed the given point from a particular point of reference.

Answer 4

Math is great. If you know it takes a car 5 seconds to go from point A to point B at 35mph then you could do the math to see how fast a car that took 3 seconds was going. Also on the highway they used the white lines painted on the side and airplanes, plus the good old I was tailing you and we where going.......

Answer 5

The two methods were following you for a certain distance, and reading their own spedometer, or clocking you from an airplane. It the case of the airplane it was either telephone poles, or markings on the pavement.

-Dio

Answer 6

Yep you're right. The good old D,S,T (Distance, Speed Time) - reliable and accurate
I have done people in this way and I have also been done myself

If you are in the UK - you will notice some motorways have white boxes painted on them. They are always the same distance apart and they are in places where there are a lack of landmarks (bridges, lamp post etc).

Answer 7

They could do a time / distance calculation such as with a
stopwatch and two telephone poles and they could simply
follow you and look at their own speedometer..

Answer 8

something like that. 2 markers, timed. not too hard to figure out.
such and such distance,
3 seconds = 10 miles over the limit
2 seconds = 15 miles " " " "

and so on and so on.

Answer 9

wow, thats crazy, i have never thought of this before. what an intriguing question!

you know the way you calculate a safe following distace? probably something like that, by counting how fast you pass by a marker, like a road sign or something.

Answer 10

How long it took for a vehicle to go from one point to another. They could use a stopwatch.