Eli5: how do traffic ticketers know that your car has been in a spot on the street longer than the time limit?

Question

I park on the street in my city and there’s a 2 hour limit for cars without residential permits. How do they know you’ve been parked for longer than the 2 hr limit? Surely they don’t have surveillance on every street and don’t take note of every car’s whereabouts every 2 hours. Do they have some type of device that can tell how long a car has been still?

In: Other

Answer 1

Some put a mark on your tire in a particular spot and if they come back later to find the mark in the same spot you didn’t move and therefore have been parked longer than the limit.

Many people just go move their car forward or back every few hours because it can’t be proven by the city that you didn’t leave and come back