Do you remember what time this accident happened? Chances are that particular car was a regular user (aka rat runner) of your street and while they might not show up the next couple of days, maybe next week they will be back - at the same time as usual.
I live in a very quiet street as well. Fortunately for me it is protected by two big spoon drains - one across the middle and one at the end - so it's hard for the locals to speed and strangers tend to bottom out.
Frosty has escaped a couple of times and she also likes to run across the road to greet her friends. So now I don't leave the door open at all ever - not unless she's on lead and tied up. A PITA but there you go. The last time she did end up in front of a car, but the spoon drain saved us and the car was not going fast. I know the owners of that car live on my street too and their dogs also sometimes escape.
Trouble is, it only takes one escape for disaster to happen. Sigh.