I can’t tell you how many time I’ve traveled around and have seen a cop driving. I say add an option to say that a cop has been seen and is moving in “said” direction. If need be put a time restriction on it so that after a certain time that alert goes away unless someone else likes it or marks it.
How would this help anyone? Do the cops always follow a predictable route in your area?
Why would any law abiding citizen need to know about a policeman driving in his car?
Do you have bionic cops with laser or radar implants in their eyes in your area? (Anyone remember the Robocop movies?)
Cops on the go can only estimate your speed roughly. That’s no basis for writing speed tickets unless you’re obviously overdoing it. Measuring your speed from a driving car precisely requires equipment which most patrol cars don’t carry around. (In Germany they use civil cars for that purpose so you won’t see them until they see you, whatever has been reported on Waze.)
Relax, most policemen have better things to do than stopping every car they spot. Drive and let drive… 
Gordonski
Standard equipment in the U.S. They can shoot radar while they’re moving, whether they’re shooting cars in the same direction or in the opposite direction. They probably use GPS to calculate the difference in speed nowadays.
Either way, you have to be doing something pretty severe to be that concerned about police presence. Waze is not an app to facilitate criminal activity.
Ya I was gonna say the cops in the US have laser radar which can be used while moving or while sitting.
Sent from my DROID RAZR MAXX using Tapatalk 2
Not all cops run constant-on K or Ka radar. They are more than capable to run instant-on which I’ve encountered 50% of the time especially if you’re the rabbit or the first car of any pack. At least around here some towns are all instant-on. If you’re not running within the speed limit you’re screwed even with a high end radar detector.
I think such feature of cops going by would be beneficial if there are large number of people reporting.
Or just stay within the limit?
David using Tapatalk
Regarding the question about police following specified routes…
Sure, it does not make sence much for local/city traffic but it does It makes sence on a highway that they may be on it for a while, especially for highways with few exits or other turnarounds.
Regarding police ticketing options while on the move…
Their cars can have calibrated speedometers. I remember a section of local road where I grew up that was marked for a set distance and police regularly stopped at both marks to check speedo calibration. They can then pull over and ticket drivers by following them and matching speed to the other moving car.