TNET—Transportation Network
Project Status
Status Update: November 19th, 2008
This November marks a major achievement for King County Metro Transit with the successful testing of replication in ESRI’s ArcGIS 9.3 environment. At version 9.2 ESRI integrated replication technology into their product line. After upgrading our systems (and documentation), we are in the final testing stage of the system with assistance from the King County GIS Center and King County Roads Services Division. Testing is proceeding smoothly and we are expecting a move to production
soon. Stay tuned, and browse the rest of this site, for details!
As always, please Contact Us and let us know if we can be of any help to you.
Project Overview
What
Is TNET? | Why TNET? | History | Benefits | Components | Database
Design
What Is TNET?
Sponsored by King County Department of Transportation and in partnership with the county’s Department of Natural Resources GIS Center, Metro Transit and Road Services Divisions are undertaking a major data development effort and integrated maintenance program to produce a comprehensive, optimally accurate and current geodatabase comprising all transportation-related spatial and attribute datasets for the King County region. This will enable King County Metro
Transit, Road Services, other county agencies such as E-911, as well as Sound Transit Rail, Washington State Ferries and the transportation planning departments of all participating cities within Metro Transit's service area to seamlessly interact with each other in geographical data terms as the region's transportation needs and issues evolve towards ever deepening complexities and interdependence. Cutting-edge technological solutions are being tested that will enable countywide multiple
data maintainers to keep the centrally stored geodatabase at optimal currency.
Why TNET?
The sharing of transportation-related geographical data has been common practice for years, but only recently has the technological infrastructure advanced to the level that allows the introduction of sharing data maintenance of a centrally stored geodatabase by widely dispersed multiple users. Until now the cross-boundary data acquired on data CDs quarterly, semiannually or even annually could be out of currency even before distribution. Spatial variances, street naming convention variances, and address range issues are some other problems experienced with this approach. Resolving such issues as well as taking full advantage of technological advances naturally led to the TNET Transportation Network Consortium.
History
During past years there have been several attempts within the Puget Sound region to produce a transportation
network that is integrated and works for all agencies. These have generally been less successful because, although
being initially integrated, the network diverges as each agency attempts to maintain its copy. These copies were
generated for a variety of reasons, including the need for data control and the ability to attach related datasets
and maintain them efficiently, and for different functions, such as planning versus operations. Most importantly, copies were
made because there was no easy way to maintain the entire network at one location and give everyone control or allow
participants to update their local copies. The TNET program will eliminate the need to redundantly maintain local copies of the transportation network dataset.
Benefits
Participants in the TNET Consortium will realize the following benefits:
- Reduced data costs
- Improved data quality
- Minimized data conflicts
- Improved participant operations
- Leveraged technology investments
- Reduced project costs through collective bidding
- Strengthened rationale for commitment to standards
- Improved support for cross-jurisdictional decision making
- Strengthened working relationships fostering broader cooperation
Components
The primary components of the TNET project are:
-
A high-accuracy data development effort.
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An application development effort that will provide a TNET Editor (for attribute data)
enabling data maintainers throughout the region to maintain a single integrated database of transportation features.
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A consortium of data owners at local cities, county departments, and other agencies
that are responsible
for ongoing maintenance.
Database Design
The database design follows the ESRI UNETRANS (Unified NEtwork and TRANSportation) model, introducing new elements required for TNET Consortium Agencies’ business needs, such as transportation mode, turn restrictions, traffic flow directionality, speed limits, weight and height restrictions. The design is complete after a lengthy iterative process. The history component is still being developed.
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