On Oct 14, 1:21 am, Mike Williams <[email protected]> wrote: > Wasn't it alan tarn who wrote: > > > > >ohh .thanks for this important information . however . do u have any > >idea on how to go about doing this "suggested route" thing? Thanks . > > Your only legal strategies are: > > 1) Throw the request at maps.google.com, and let it do the suggestions, > i.e. open a new browser window and pass it something > likehttp://www.google.com/maps?f=d&source=s_d&saddr=Jurong+West,+Singapor... > ddr=Ang+Mo+Kio,+Singapore&hl=en > > 2) Just display the normal route and the avoid highways route. > > 3) Try to guess sensible waypoints to add in the middle of he route that > might lead to reasonable alternatives. That's not easy unless you have a > database of highways or highway intersections, and can look for such an > intersection that's somewhere between your start and end points (for > some approximate value of "between"). > > There may be problems using lat/lng coordinates for the waypoints, > particularly if there's a dual carriageway involved. If the coordinates > are for a point on the wrong carriageway, GDirections will drive a > considerable distance out of your way so that you visit the wrong side > of the road. But even using street names you may well get strange kinks > near the waypoints, like this: > > from: Jurong West, Singapore to: Ayer Rajah Expy singapore to: Ang Mo > Kio, Singapore
Interesting: http://www.geocodezip.com/example_geo2.asp?waypts=yes&addr1=Jurong+West,+Singapore&addr2=Ang+Mo+Kio,+Singapore&waypt=Ayer+Rajah+Expy+singapore&geocode=1&geocode=2 -- Larry > > Perhaps the only way to really deal with that is to include points on > both sides of a dual carriageway, and well clear of roads that cross > underneath or overhead, and then try to filter out the ones that are > silly. > > Consider these examples > > from: Jurong West, Singapore to: 1.32558,103.740764 to: Ang Mo Kio, > Singapore > > from: Jurong West, Singapore to: 1.32582,103.740764 to: Ang Mo Kio, > Singapore > > One of those adds 7 minutes to the trip by a complicated excursion to > visit the wrong side of the road. > > Writing code to filter out silly routes isn't easy. As a first > approximation, you could discard routes that have estimated times that > are more than, say, 10% longer than the initial route. And you can also > compare the durations for pairs of points on opposite sides of a dual > carriageway and always discard the slower one. > > Writing code to discard duplicate routes isn't easy either. For example, > a point on Bukit Timah Expy or Kranji Expy might create a route that's a > duplicate of Google's Seletar Expy suggestion. > > -- > Mike Williamshttp://econym.org.uk/gmap --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Maps API" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/google-maps-api?hl=en -~----------~----~----~----~------~----~------~--~---
