Help me bend Google Maps to my will....

January 26, 2007 11:54 AM

Help me bend Google Maps to my will....

At work, I very often need to use the "Get Directions" feature of Google maps to plot directions from a specific highway exit to another specific highway exit. (For instance, right now I need to create directions from Exit 113 on I-95 in Augusta Maine to Exit 38 on I-495, which is somewhere in Massachusetts.) However, Google Maps (or, really, any other on-line direction-giving sites I can find) can't seem to recognize the exit numbers as locations, despite the fact I know they must know where they are.

Is there some hack for this that I'm not aware of? Right now I wast a lot of time trying to Google up a business or other address that is near the exit, and plot my directions to and from those directions, but that wastes a LOT of time and can be a huge pain.

PS: downloading Google Earth is not an option.

posted by anastasia to computers & internet (8 comments total)

It's a bit cumbersome (although probably less cumbersome than Googling nearby businesses), but this interstate highways browser will give you a Google Maps link to a specific junction, like this for Exit 38 on I-495:

http://maps.google.com/?ll=42.627769,-71.272003&spn=0.015000,0.015000&om=1

If you copy and paste the "42.627769,-71.272003" bit into the text box on Google Maps, you can use it to get directions to and from that position.
posted by chrismear at 12:09 PM on January 26, 2007 [1 favorite]

If you know what road the exit is, you should be able to use the cross-street to determine location (ie, "I-95 at Downeast La., Augusta, ME to I-495 at Eastawoosta Rd., Chelmsford, MA"). As long as you pick a town reasonably close to the exit, Google Maps can usually figure out where you mean.
posted by uncleozzy at 12:11 PM on January 26, 2007

Exactly- the exits themselves aren't really "points" on the map- exit numbers are all are usually just mile indicators, i.e. Exit N is N miles from the starting border- but the roads that the exits turn into are valid points- so those are the points you can use driving directions for.

Can't you just create driving directions from the towns of each exit, and then trim the driving directions leading up to and after the start and end exits?
posted by hincandenza at 12:17 PM on January 26, 2007

hincandenza: "Exactly- the exits themselves aren't really "points" on the map- exit numbers are all are usually just mile indicators, i.e. Exit N is N miles from the starting border- but the roads that the exits turn into are valid points- so those are the points you can use driving directions for."

Out west this is often the case (I remember seeing a whole lot of this in Arizona), but here on the east coast the numbers are generally arbitrary (but at least monotonically increasing/decreasing depending on direction).
posted by Xoder at 12:58 PM on January 26, 2007

Moreover, sometimes exits will have both an old and new number, the new number being more in line with the mile indicators.
posted by odinsdream at 2:49 PM on January 26, 2007

That is never done in Massachusetts, AFAIK. Exits are numbered consecutively from 1, starting at the state line, if the road crosses one. New exits usually get the same number as an adjacent one, with an "A" appended. Sometimes the exit numbers appear to have some relationship to the intersecting route (on Rte 3, exit 26 is rte 62; exit 29 is rte 129), but it's just coincidence.

The mile-numbered exit system is also used in the South, I believe. It is a better system.
posted by Kirth Gerson at 3:46 PM on January 26, 2007

The mile system is also now used in at least some parts of Pennsylvania. Out near Erie, PA you'll see mile labeled exits with a small sign underneath saying "Old Exit #X".
posted by Jahaza at 10:07 PM on January 26, 2007

I'd love to know how to search for exit numbers in google, though. It seems obvious that google knows where they are, because they're directly involved in the directions it gives. The numbering system used shouldn't be a concern.
posted by odinsdream at 9:22 AM on January 27, 2007