David et al, I've mostly lurked on this list, but this a good opportunity for me to de-lurk and offer some clarification... The Census Bureau uses the transportation geography in support of its central mission, which is the constitutionally-mandated census and demographic profiles, -not transportation applications. Thus, it's very difficult for the Census Bureau to justify the added expense of collecting turn restrictions, speed limits, and so forth. On the other hand, state DOT's and USDOT have far more need for those attributes that support routing and network connectivity. So, your second line of questioning, with regard to helping to create the intergovernmental relationships necessary to add on to the TIGER geography may be a better focus for discussions on this list. Where does it make sense for USDOT (and state DOT's) to team up with Census to add this level of attribution? How would this process be governed and how would the governance process insure that the missions of both Census and DOT were met? Lastly, how can this list be used to generate and advance the kind of collaborative partnerships that could enhance TIGER and other national data resources? Hope this helps brings the discussion into sharper focus, Steven
________________________________ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of David William Bitner Sent: Wednesday, April 25, 2007 11:03 AM To: [email protected] Subject: Re: [Geowanking] Map Image APIs Charles, I understand that routing improvements are not in the budget as they are not required for any Census operations. However, The Census Bureau must realize that they produce the only publicly available nationwide dataset of this type that has far broader applications than their own internal business needs. What can we do as a community to try to help secure funding or to create relationships with other government agencies (federal or otherwise) to whom these enhancements would be valuable? With a dataset as import as this street data is, we need to make sure that we keep the blinders off. David On 4/24/07, [EMAIL PROTECTED] < [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > wrote: I don't think there will be any further releases of TIGER/Line Files (see http://www.census.gov/geo/www/tiger/future/future_tl.html), though the information will be released in several other forms, once or twice a year. The underlying database will have more accurate coordinate information for more counties, as the MAF/TIGER Accuracy Improvement Program completes, but new data that would help with routing, such as turn restrictions, speeds, and one-way streets, are not included. They are not in the budget, and not required by any planned operation that would justify them in the budget. Charles Dingman, Geographer/301-763-1120 4H040, Geography Division US Census, 4600 Silver Hill Rd Stop 7400 Washington, DC 20233-7400 "Tom Longson (nym)" <[EMAIL PROTECTED] To m> [email protected] Sent by: cc geowanking-bounce [EMAIL PROTECTED] Subject Re: [Geowanking] Map Image APIs 04/24/2007 05:09 PM Please respond to [EMAIL PROTECTED] burri.to >From what I understand using TIGER for routing is a bad idea because TIGER doesn't say which roads are one way, on ramps, off ramps, etc. Could be potentially dangerous, although very cool regardless. I personally love this... "Graphserver will return an itinerary between any two connected vertices, even if the itinerary is absurd. In this case traveling by bus and foot from downtown Seattle to deep within the foothills of the Cascade Mountians involves an eight-hour hike from one of the most remote bus stops in the county." - http://graphserver.sourceforge.net/img/absurd_route_large.png Anyone have info when the next release of TIGER is expected, and if it will have more data to solve some of these routing problems? Tom Longson ________________ CAR&D / Cars.com On 4/24/07, Paul Ramsey < [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > wrote: Ryan Sarver wrote: > We run mapserver internally and I was trying to avoid it as a > consumer-facing app could be pretty taxing on the system. It's much more > fun to use someone else's resources :). But its sounding like that might > be my best bet. Robust at a software level, not so much at a "good answers" level. Using TIGER for routing is contraindicated. -- Paul Ramsey Refractions Research http://www.refractions.net [EMAIL PROTECTED] Phone: 250-383-3022 Cell: 250-885-0632 _______________________________________________ Geowanking mailing list [email protected] http://lists.burri.to/mailman/listinfo/geowanking <http://lists.burri.to/mailman/listinfo/geowanking> _______________________________________________ Geowanking mailing list [email protected] http://lists.burri.to/mailman/listinfo/geowanking _______________________________________________ Geowanking mailing list [email protected] http://lists.burri.to/mailman/listinfo/geowanking -- ************************************ David William Bitner
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