When they have the siren on, they're typically driving much faster than normal, but normally they're indistinguishable from a normal driver.
The one incident I did see was a motorcycle officer do a U-turn across four lanes to come ticket me (no seatbelt). He turned on his lights first, and the road was relatively clear.
[edit] To put this in the context of the article, if a Cop does something publicly stupid in a small town, there will be a social penalty levied against them when they e.g. sit down for a beer next to someone who saw them do something stupid.
~35k population.
I have no idea who any police officers are, nor have I ever (knowingly) sat down next to one...anywhere. I occasionally see a group of them at Arby's or something, eating with each other at lunch.
FWIW I have a very wide social circle in town, here (I own a bar)--but it includes no police officers.
I guess so. I've seen it more times than I can count.
The only problem with this is that the cop car probably deserves a class of its own, even riskier than the swerving distracted-driver minivan full of kids.