In my neighbourhood, there was a small circle of burned grass near a bus stop where a careless smoker tossed their butt. This is a popular stop, and despite someone actually placing an urn there with sand, almost all of the discarded smokes end up on the sidewalk, or in the adjacent yard.

This is no doubt the reason why Richmond is simply just closing trails in some of the parks.  Because some smokers think everywhere is an ashtray,  everyone has to stay off the trails.