Hello Peter, Michael, Josh and Geowankers, Thanks for the detailed description of the problem and for the potential solutions.
Does anyone know if there already exists a tool that canvassers can use? Peter is correct that time is of the essence so there isn't any time to develop anything. Or, are there any folks in the group willing to put in some volunteer time to quickly create something? Jennifer Peter Batty wrote: > This is actually a (somewhat constrained) traveling salesman problem > rather than requiring a point to point route, so Google Maps routing > won't help you. pgrouting supports traveling salesman but I haven't > used it and don't know what a practical number of points to handle is > - traveling salesman is a complex problem of course. I was out > canvassing for the xxxxx campaign recently (the number of x's is a > clue, in my case at least :) !!), so was an end user of what I assume > to be the same system here. Of course I immediately wondered about a > better automated solution than they had also. > > I thought it was an interesting problem though so it's worth > explaining it in a little more detail based on my experience. We went > out in pairs, and were each given a package of paper sheets. The cover > page had a printed Google map with markers indicating the houses we > were to visit (this was the same map for both of us). Then behind that > we had a set of printed sheets, one or more per street, listing the > houses we needed to visit on each street in numerical order, with > details about the person/people to talk to at that house. We were just > visiting houses of known sporadic supporters and independents, so it > was a subset of houses - in this case it would vary from maybe 1 to 4 > out of every 10 houses. One canvasser had odd numbers and one even > numbers, so you would do opposite sides of the street, so you had > someone in the same general area for support. Often you would have > more houses in a block on one side of the street than the other, so > one person would get ahead of the other. In the area that we were > canvassing, the blocks were long and thin, so we ended up walking > along the blocks "lengthwise" as most of the addresses we had were on > the north-south streets, but it was hard to tell if you were close to > a house on one of the east-west streets (on a different page from the > one that you were currently looking at). We ended up missing out some > of these. In total we had 90 houses in the package, 45 each. > > So what we really wanted was to each have a list of our 45 houses in a > suitable order for us to visit (as opposed to being listed street by > street in numerical order), with a map showing the route. Doing the > odd / even thing properly is an extra complication (i.e. taking 90 > houses and coming up with two routes, which ideally keep the two > people close to each other). The simplest initial solution to this > would probably be to take all 90 houses, come up with the best route > to all those, and then just split it into odd and even after doing > that. If you got that working, then you could look at something cleverer. > > It seems as though for pgrouting you would need to have a reasonable > street network, which you may or may not have. In some cases, > especially if you had a pretty dense set of houses to visit, you might > be able to get a reasonable solution just using the locations of the > houses and ignoring streets altogether - but clearly in some cases > this would not work well. > > A pragmatic short term solution might be a semi-interactive one - > display the houses to visit on a map, let a user sketch a line > visually with an approximate route, buffer around that and find all > the houses close, and sort them appropriately based on that. And have > the ability to highlight any houses that were not yet added to the > route, etc. I suspect that for a short term solution (which is > presumably what you need), given the challenge of getting a good road > network, etc, this approach may be your best bet. It would need a bit > of custom development though, unless someone happens to have something > like that lying around. > > Cheers, > Peter. > > On Thu, Oct 16, 2008 at 12:01 AM, Josh Livni > <[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>> wrote: > > pgrouting if you have the street data in postgis would be one way. > > tho as long as they're drawing over google maps, why not insert a > little javascript to use the gmaps api routing? > > -josh > > > On Thu, Oct 16, 2008 at 1:03 AM, Jennifer Strahan > <[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>> wrote: > > Hello Geowankers, > > I'm forwarding this email from a colleague in hopes that > someone will > have some suggestions to pass on. > > Thanks for the help. > > Regards, > Jennifer > > ps. I've stripped out political references.... that's why > you'll see > xxxxx campaign. > > -------- Original Message -------- > Subject: GIS routing question > Date: Wed, 15 Oct 2008 14:32:43 -0700 (PDT) > From: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > To: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > CC: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>, > [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>, > [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>, > [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>, > [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>, > [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>, > [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>, > [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>, > [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>, > [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > References: > <[EMAIL PROTECTED] > <mailto:[EMAIL PROTECTED]>> > > > > Hi All > > My partner is working for the xxxxx campaign and was asked by > the regional campaign office to look for computer-based > routing solutions for canvassing. > > Nationally, all the campaign offices use a networked, > web-browser-accessible database called VoteBuilder. It manages > contacts and lets field coordinators define canvassing > territories by drawing over a Google map. > > VoteBuilder doesn't construct a route for the canvassers-- > that's up to them. In suburban neighborhoods with winding > roads and cul-de-sacs it's almost impossible for them to come > up with an efficient route that doesn't miss some of the > households. > > Some of the local and regional offices have adopted software > solutions for routing, but the techniques aren't being > disseminated. > > I know there's an extension for ArcGIS to do routing. Is this > the only solution? > > Thanks for any suggestions.. > > Louis > > > > > > _______________________________________________ > Geowanking mailing list > [email protected] <mailto:[email protected]> > http://lists.burri.to/mailman/listinfo/geowanking > > > > _______________________________________________ > Geowanking mailing list > [email protected] <mailto:[email protected]> > http://lists.burri.to/mailman/listinfo/geowanking > > > > > -- > Peter Batty - President, Spatial Networking > W: +1 303 339 0957 M: +1 720 346 3954 > Blog: http://geothought.blogspot.com > ------------------------------------------------------------------------ > > _______________________________________________ > Geowanking mailing list > [email protected] > http://lists.burri.to/mailman/listinfo/geowanking _______________________________________________ Geowanking mailing list [email protected] http://lists.burri.to/mailman/listinfo/geowanking
