On the Peninsula the obtained state money to build pedestrian overpasses over simple main streets that normally use crosswalks. They then built them with these steep ramps with 90 degree turns every 30 feet or so. So of course no one uses them. They just walk down to the corner and push the pedestrian crossing button.
In one place there is a freeway overpass that actually goes into an open field. When I do the Mission San Juan Batista (John the Baptist) ride you weave around through the back farm roads since the highway was converted to a freeway. Coming back you have to ride along a state highway that is heavily used by interstate trucking. But it has a 20 foot wide shoulder and you don't have any troubles. Then there is a turn onto another state highway with high speed traffic and while the shoulder isn't that wide, it is wide enough that you don't feel threatened. We then ride up into the hills to the west of the freeway and top a peak and ride back down to Monterey Rd. which used to be the main route to Monterey from the bay area. We usually park behind a gas station there and do the 45 mile one way and 55 the other. This is a quiet ride except for that 8 miles on the highways.