The idea of geometry is the same for each system from national GIS datasets; to small datasets used to track each fire hydrant for a city. You are correct you need a bit of information about each data set (units, projection, when the data when collected and what accuracy).
You may consider looking at CityGML which is intended to be an interchange format for city scale information; all there demos seem to be visual fly-through etc... As for having information about lanes and so forth; that is real up to your data provider; often that information is not available for free. Sometimes you can source it from councils or local governments; but be aware that it may not be set up for navigation (indeed it may of been collected for another purpose such as maintenance or council asset management etc...). So the good news is they may be recording the lines of paint on the road; the bad news is they may not be recording what those lines mean in terms of where cars can turn. My best advice would be to approach a local council and offer to use their city as a pilot for your program and see if you can arrange data access in that manner. Jody On 04/08/2010, at 10:07 AM, berryman wrote: > > Hello, > > I am hope to use GIS for a traffic analysis program that I am involved with. > After having looked at a couple weeks worth of GIS resources, I still feel > like I haven't found what I'm looking for and it's time to get some human > input. > > The main source of my frustration is that all of the standard data formats > seem to be too general for my purpose. Common formats provide the ability > to encode points, lines, polylines, and polygons (where the locations are > unitless). But I need the ability to encode the geographic location (e.g. > lat/long, NAD83) of high-level constructs. For instance, I'm not just > interested in the location of streets, I'm interested in the location of > each lane. I also need to know how street topology and traffic direction so > that I can make path planning determinations. Finally, it would even be > ideal if I could encode the location of traffic signals, stop signs, > bus-only lanes, etc. > > I know that these types of encoding must exist somewhere , because my Garmin > GPS understands the rules of the streets and can anticipate things coming > up. For instance, it might tell me "stay in the right lane." Are there > standard data formats for encoding this information? Or is the ability to > encode this a non-public extension of some more generic standard? If so, > then how do I go about extending some other standard for my application? > > Thanks all! > -- > View this message in context: > http://osgeo-org.1803224.n2.nabble.com/Data-format-frustration-too-general-tp5370620p5370620.html > Sent from the OSGeo Discuss mailing list archive at Nabble.com. > _______________________________________________ > Discuss mailing list > Discuss@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/discuss _______________________________________________ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
