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

It’s actually super simple. In my City at least they carry a piece of chalk and when they walk by they mark the hour on a tire. When they walk by again they glance at the tires. If there is chalk they just do the math.