Oh, I know what you meant and you are describing me the other day. I went over for Strong Water (after taking water taxi back to Sapphire), but by the time I was ready to go back to CBBR and was slightly confused on how to get back unless I crossed the street.
Directing to the VB tunnel will definitely work for legal reasons. Doesn't mean people won't still cross, but it would be 100% on the person crossing at that point. They need to do better than just a chain linked fence to get the point across that they don't want people to cross. Hell, put up a "NO CROSSING" sign. That should get it across.