Any time a cop tries to trick you into incriminating yourself by asking you a question like "Do you know how fast you were going?" where giving any answer could be bad, i'd recommend just answering the question with a question, "How fast?". If he continues to badger you, simply remain very polite and refuse to directly answer any question and pass the response requirement back to the cop.
Had this a couple of times in the UK. It's a new tactic here. I think they learned it from some naff US cop reality show.
Neither time was I actually speeding. It was an estimate on their part and both were in an area with a good probability of bagging a moron who confesses immediately out of confusion.
Usually results in a frustrated piggy who asks to search the vehicle[1] which you don't have to agree to, insurance check, vehicle check and a warning to drive more carefully (bear in mind 450k miles driven, 22 years, advanced and clean driving license, no insurance claims, no speeding tickets, no parking tickets ever).
[1] I have considered purchasing a large quantity of cheap sex toys on Alibaba to keep in the back to make it embarrassing for them when I do agree for a search to be made...
Are you not required to know what speed you were driving at? How else would you be able to stay under the limit?
I don't get pulled over often, but the last time that I got pulled over I told the officer that I believed I was going the speed limit. It's a subtle distinction, but it seemed to work as he had no other reason to pull me over and didn't write me a ticket.
I suppose it depends what is the intended meaning of the question - you want my average speed over the last few minutes? Since you've been following me? The latter is probably the intended meaning and, in that case, I really can't be expected to know.
I've heard both that you should not answer for fear of incriminating yourself, and that you should answer because not knowing how fast you're going means you're negligent and that's also a crime. (I'm neither a lawyer nor know which is the better choice)
IANAL, but the way I've had it described to me is not knowing exactly how fast you're going is not negligence, as it's always a better idea to keep your eyes on the road instead of a speedometer. Hitting people is a potentially more serious crime than speeding. I'd love to hear a lawyer's take on this, however.
"Do you know how fast you were going?" "Well... 38...40?" (In a 35 MPH zone).
I was told to always say "No, Officer, I don't know why you pulled me over". This seems to be a good idea now, as it cannot be seen as a confession. What should you say when the officer pulls you over? Can you plead the 5th and say nothing? How well does that go over?