Good area to ride your bike safer than on most streets. Open enough so if you have a little patience it's easy to navigate through walkers. i used to do it in the early afternoon and there was less traffic. It would be a decent and safe place for wheelchairs as well.
This is a favorite loop. Easy enough to take people of different levels and make sure all make it. For those who like more effort just increase the speed and wait at selected spots for the rest. You go through areas of West Contra Costa that you usually drive but never notice the bicycle path. It's always fun. This was my second time this year.