The Friday Cyclotouriste

In a previous post, I described a new option for getting bicycling directions from Google Maps. Now I’m wondering how this feature deals with odd, highly impractical, or even impossible routes?

Trying to fool Google’s programming elves, I requested directions to a location on the other side of the Bay (i.e., a route from San Rafael to Berkeley).

The challenge, of course, is the bridges; they don’t allow bike travel (except for the Golden Gate Bridge). But Google Maps didn’t blink.

Rather than sending me on an ill-advised circumnavigation of the entire San Francisco Bay, I was instructed, as you can see in the screen shot below, to ride to Larkspur and to put my bike on the Golden Gate Ferry to SF (and then to catch the SF ferry to Oakland) before taking an overland route to Berkeley.

In urban planning circles we call this multi or mixed-mode commuting.

I was surprised Google Maps came up with this solution!

Google Map example

Bicycling directions user interface

Google Maps today added the option to get Bicycling directions (in addition to Walking, By car, and By public transit). This comes after more than 51,000 cyclists signed an on-line petition urging them to do so.

Google explains how the new feature works here.

For some reason these maps cannot be embedded yet in web pages, but above are some screen shots I made of the new interface and the map generated when I made San Francisco the destination.

Google engineers employ some fancy algorithms to deal with the problem of steep slopes and hills:

Our biking directions are based on a physical model of the amount of power your body has to exert given the slope of the road you’re biking on. Assuming typical values for mass and for wind resistance, we compute the effort you’ll require and the speed you’ll achieve while going uphill. We take this speed into account when determining the time estimate for your journey, and we also try hard to avoid routes that will require an unreasonable degree of exertion. Sometimes the model will determine that it’s far more efficient to make you ride several extra blocks than to have to deal with a massive hill.

Does it work as advertised?

• For the route to San Francisco it missed some smaller bike paths (e.g. the one behind the College of Marin along the canal). Overall, it seemed to make good, safe choices and no blatantly dumb ones.
• However, for a shorter trip to San Rafael, Google had me riding down the Miracle Mile rather than on Greenfield Avenue, which is really, really dumb.

At the very least, this beta version is a useful starting point for getting bicycling directions (and it will certainly become more reliable over time as users report problems).