Every time I sleep in a different parking (rarely do I sleep on the side of the road) I have to learn to listen to the noise around me. I’m usually concerned with being harassed, so I pay attention to cars that sound close by. I try to identify the kind of motor that is running because cops use deeper sounding motors. The deepest sounding trucks are the semis. Cops motors are in between.
In some parking lots I learn that a lot of cars pass by me and I need to ignore them all. There is too much going on around my car for the cops to bother with me. But if I’m parked in a more isolated spot then any sound of a car is a cause for alarm. I usually want to be awake and telling the cop that I was not sleeping in my car and breaking the law.
I like to think of myself as a light sleeper, but there have been a few times where the cops have to wake me up and harrass me. I bet they find a lot of joy in waking car sleepers up late at night. Being stunned about what is going on can be very stressful. All of a sudden cops appear right on your window and you have to wake up and calm down at the same time. I get scared that I might act aggressive while waking up and get shot.
Hearing people walking and talking is not really a concern to me. Usually, if they are a thief, they will be very quiet. My best protection against thieves is assessing potential areas to sleep. Some spots look more vulnerable than others.
When I hear the street sweeper, I feel a little guilty parking in my spot because they can’t clean there. But no street sweeper has ever asked me to move. I’ve probably had about 5 sweepers go around my car. Some will wake me up with their loud noise, but it doesn’t seem like a big concern. I figure I will probably be in a different spot the next week anyway.