Oh yeah, the checkpoints as of today are now gone. You are free to drive into Chapman to volunteer. However, they do not want a bunch of sightseers clogging up the streets. If you are there just to be a "looky!, looky!", you will probably be asked to leave. It is way too dangerous to have people just looking at the damage in the city right now as there are lots of crews working with front-loaders, dump trucks, and other huge equipment trying to remove the debris.