[personal profile] dmaze
What happens if you try to ask the much-discussed Google bike directions service how to get out to 495? The results are less impressive than they could be (and didn't match my obvious routing).

The two routings it gives me both go out along the Minuteman. From the end option (a) goes down the Reformatory Branch trail to Concord, through the Concord Rotary, and up 2A; option (b), for an extra half hour, goes up the Narrow Gauge trail and continues up through Billerica and Chelmsford before coming back via 110. Dragging the line around, I can also get Bedford-Concord-South St-225, or Bedford-225-Carlisle, then cutting across back roads to 2A. Forcing it onto 225 the whole way gets a time just very slightly worse than its best route.

One obvious implementation detail here is that it has classifications for roads. Beyond the city of Boston, it seems to have "bike path", "bad", or "forbidden", and so while it's clever enough to not put you on to route 3 it doesn't really understand that 2A isn't a great routing, or that 62 and 225 are practically bicycle superhighways on the weekends. I also can't tell it that I have a road bike and so I'd much prefer 62 to the Reformatory Branch trail, or 4/Concord Rd to the Narrow Gauge trail.

I can also think of at least one path that Google is outright missing (ex-NH/OC north from 225 at 27 to Chelmsford). It has the little bits of path in Winchester between Winchester Center and Horn Pond, but doesn't really call out the residential streets connecting them (I think they are signed "bike route"). And for that, I'm a little surprised that West Roxbury Parkway shows up in bright (bike path?) green with its several rotaries, and that VFW Parkway there is in dotted (signed bike route?) green when I wouldn't ever take my bike there.

So yeah, this isn't really going to replace the Rubel paper maps for my local trip planning any time soon. I appreciate the effort, but for longer-distance trips so much of the engine depends on having good data that just isn't there right now.

Date: 2010-03-11 05:12 pm (UTC)
From: [identity profile] fredrickegerman.livejournal.com
"Unpaved" and "must carry" seem like important missing facts for various links.

Date: 2010-03-11 05:14 pm (UTC)
From: [identity profile] fredrickegerman.livejournal.com
Whoops. For example, plotting ET -> MIT (not 77 Mass Ave, but MIT, which lands you at the base of the Harvard Bridge) sends you across the footbridge onto the Esplanade as a bike route.

Profile

dmaze

Expand Cut Tags

No cut tags
Page generated Jul. 20th, 2017 02:31 pm
Powered by Dreamwidth Studios