Tickets are now sent to motorists via mail, and are no longer left in yellow envelopes under a vehicle’s windshield wipers.
A motorist can tell if their vehicle is in violation by observing the meter stick closest to the rear of their vehicle. A green light means you are paid up and a red light means you are in violation mode and could receive a parking ticket.
If you find your meter stick is red, you can true-up -- that is, pay for any 'expired' time before you leave the parking space. Doing so ensures that you will not get a ticket, as long as you have not exceeded the maximum time limits.
More information can be found at https://www.romi.gov/1553/Parking-in-Downtown-Royal-Oak