Here’s an Euler tour of the Bay Area! Of course many more such tours are possible. The one I have here is 165 miles long and it will take an estimated four hours to drive around the loop. It should be a fabulous day out for a photographer!
For those not well-versed in Computer Science, an Euler Tour is a path through a graph that traverses each edge exactly once. In this particular case, bridges are the obvious edges. Nodes aren’t completely clear though since the land masses are amorphous and not clearly demarcated from each other. For my purposes, I assumed there are three distinct nodes corresponding to WestOfBay (SF, SouthBay, Peninsula etc), OverTheBay (Marin, Sausolito etc) and EastOfBay (Walnut Creek, Fremont etc).
Can you come up with a shorter Euler Tour which covers all the Bay Area bridges? One condition your tour must obey is that the stops in the tour must be city centers and not arbitrary points on the map. For example, in the tour that I display here goes as follows: Redwood City -> Hayward -> San Francisco -> Sausolito -> Rollingwood -> Vallejo -> Walnut Creek -> Fremont -> Redwood City.