Alto Tunnel

In Marin County, north of San Francisco, there is a great bike path that runs along the bay connecting several cities. It uses a right-of-way originally created for a commuter rail line that ran up to sometime in 50's-70's (I really have no idea - before my time at least).

Currently, the bike path just dead ends into a hill. If you want to continue to ride, you are forced onto surface streets and have to deal with a lot of traffic and a fairly narrow shoulder.

However, there is a tunnel through the hill. On the other side there is a residential neighborhood, and then a fairly straightforward connection to link back up with a Class II bike path.

Why not open the tunnel?

Well, it will cost money, and there is the inevitable disapproval from the residents on either side of the tunnel. Why? Well, of course the increased crime that would come along with bike commuters! Huh?

You can read more here.

And here is a video on the issue from who knows when.