@PamelaSchure A3. There are lots of little paths that work, especially in Berkeley where there are giant concrete planters that were probably originally meant to keep people out of neighborhoods but now function as walk/run/cycle permeable road barriers. These work for walking though too.
There are some places off of trails that are not reachable by car directly, but require kind of a longish walk/hike that are faster to get to by bike.
Ahh, one other thing that's sort of related: the trick where you can hang a pannier on a grocery cart when shopping.