Ideally you ask them if they know how fast they were going. I know exactly where the posted signs are on the highways and urban roads so they either know and admit (usually a verbal warning and release if light traffic) or they play the “Ive no idea game, how fast was I going?” game. Wrong move.
Speedometer doesn’t work = equipment violation.
“I wasn’t really paying attention” = inattentive driving.
“It was only 10 mph over” = on a 50 mph urban thats 20% over, hard to explain in court.
“Not my car” = twice ended up stolen or joyriding.
Just be truthful and 99% of the uniforms will release with warning. Exception is in school zones, pretty heavily enforced for a reason.