There's a reason most of the speeding cameras don't trigger until you've done some percentage above the speed limit.
Yes, the reason is that a cars speedometer is not a finely calibrated device and the average driver doesn't really know if they're going 44 or 53 when their speedometer says 50.
How many judges do you think would throw out a speeding ticket if you were doing 50.5 km/h in a 50 km/h zone? Would you even be able to tell if you were going 1% over the speed limit? Shall we also have police start handing out fines for jaywalking on empty streets?
See, you answered your own question, so you know your analogy is absurd. Drivers CAN tell that their car is in the intersection and they CAN tell whether their car has a speed of zero (i.e. come to a complete stop). If the law is not going to be enforced then it shouldn't be a law.
Shall we also have police start handing out fines for jaywalking on empty streets?
Yes they should. Then maybe those poorly written jaywalking laws would be repealed rather than be an opportunity for the police to hassle whoever they sort of feel like shaking down that day. If YOU don't think the law is useful then your solution is to just violate it when it suits you? Why not advocate for a clearer, more useful law instead?