I am fortunate to live near a paved bike trail, so I can usually take that to wherever I need. My biggest issue is dog walkers who walk on one side of the trail and their fido walks on the other, with the leash basically transversing the trail like a finish line tape. I don't blame the dog though, this is a owner walker problem. One that seems obvious but isn't apparently. The other is with people wearing all black at night while walking/running/biking. I run and bike and always have lights of some sort, but am confused as to why it is my responcibility to carry lights and see them, I think one would want to take their own safety seriously and be proactive.
When I commuted on the streets, the vehicle passing me within a short distance of a stop sign or side road, then turning right in front of me or making me stop to wait for them to make the turn, is lame.
Waving us through is nice, but sometimes drivers don't realize we have to follow vehicle rules and have to act as they do. If it isn't my turn to go, it isn't my turn to go. Stop light, stop sign, turning either direction, etc. Just worry about how you are driving and leave the biking up to me.