There are systems that can tell when people are smoking in prohibited areas or littering from high-rise housing

With the help of cameras the government monitor crowd density, cleanliness of public spaces and the movements of every locally registered vehicle

There are smart street lamps (Barcelona) which adapt and dim when there's no movement on the road

Parking sensors : they collect the data about whether the plce is vacant or not

Garbage sensors which are actually compact drop-off containers which have a vacuum network through pipes which sucks up trash below ground