Thread: Creating our own GPS maps

Speed Limits
Automatically generated according to the speed travelled on by each users of the system. Can change along one street. Not sure how you would cope with people who speed and that.

Street Names and Point of Interest
Entered by users. When a map is downloaded and used by another user they can agree with or modify the name of a POI or a Street Name. You would need to introduce something of the concept of 'trust'. The more accurate someone is at entering 'data' the more their entries 'count'.

This would weed out people screwing with the system.

I don't think that would work somehow. The way companies do it is to physically drive up and down every road on the map, then sit down and start programming in street names, direction of travel etc. You have also got to have a method of identifying where one road stops and another begins.

I imagine a small app to scan paper maps, stack your (vectorized) gps log on top of it. Then you can rescale it to match the map. Coz you have a real map to works with, you know where streets end, and you have their name. Once done, that portion of data is made available over p2p. Each day, your puter get new datas, and rebuild itself its database.

A rainy sunday and nothing to do ?, well scan your city map...

I have very often thought of the same thing. I live in Norway, and digital maps are very expensive here. I wrote my own GPS software for use in geocaching and I started logging and plotting GPS data on my laptop when driving. It should be possible to gather and organize data such as these to the point where it becomes a useable roadmap. It would be nice to have a public domain roadmap.

Here is one thing to think about: Such a ploy can only succeed if each user of the system can use it on their own for quite some time. If I'm going to use that software to produce maps from my logs, it almost has to give me instant gratification. Everytime I enter the name of a street, that street should "work" in my local map data.

Uploading and combining would probably be secondary for some time. I don't expect such an initiative to catch on for some time, here in Oslo atleast.

So if someone is already starting to code, concentrate on the user-near components, the server and combining bits can probably wait.

For the most part the maps come from somewhere public and are parsed into a proprietary form for each companys map software. I myself have been writing map software (just started a new project which is a VB6 open source clone of iguidance, minus the routing for now) and the US source for the maps is the TIGER/LINE (http://www.census.gov/geo/www/tiger/) data and is avaliable for free.

The only flaws I see with the tiger line data over comercial maps is 1. A lack of distinguishing major roads between minor roads (for example tiger describes "sunfish lake blvd" the same as "132nd st", it only makes distinguishing features on higways and freeways), 2. A lack of exit numbers on freeways, 3. A lack of showing which roads are 1 way roads, and 4. A lack of points of interest that isn't parks or schools.

However, I think this data is also publically avaliable as well in different places (I saw a file containing the US highway system which included blvds; http://www.gis.fhwa.dot.gov/gisData.asp), and I can import a phonebook (http://cal.phonelosers.org/forum/news173.htm) and locate different addresses from a phonebook to make a giant POI database with every business/person in a city.

HOWEVER, all that aside I agree it would be nice to have "smart routing software" that learns where paths are on the roads based on where you drive and the direction/speed you drive in, which would be especially usefull for people that live outside the US/europe, but that sounds like alot of work.

I guess the whole idea is that you wouldn't have to do a whole town. It would rely on a constant stream of new information from lots and lots of users. From this it would generate maps.

You wouldn't need to program in things like directions of travel because the system would have already realised it was (for example) a one-way street because the only data it was gotten is going in that one direction on that street.

Only quirks I can see would be the entering of street names, the fact that would need multiple users and to join the maps in some way (otherwise it would only be good at showing you how to get where you've already been ), and stopping people from screwing with the system.

Originally Posted by Nomad

That sounds intersting but when you can buy a porgram like MS Street and Trip for about $ 25.00 for the full USA. It would cost more than that for the gas to do a small town.

I was not clear: I don't see it as "drive all your city then name the streets" for other ppl, that would be stupid, fuc...ly expensive.

I mean, where I live ppl get once a year in their mail box a little book where stores, professionals are listed, where you can find all informartions you may need about city service's, emergency numbers, who and where are doctors, vets, whats pharmacy is open at night... And a little map of the city (A3 papersheet).

Scan that map, use an app to vectorize it (or a part of it if your too lazy), fit your gps log with that map, and let the app recompute a database.