National Street Network Data Evaluation

1. National Street Network Data Evaluation and Performed by the OEI/OTOP/NTSD GIS Team RTP, NC - 8/19/03

2. Data Sources • TeleAtlas MultiNet North America “Shape 4.1” (2002.4.1) • GDT DynaMap/2000 version 12.2 2002 (MD only)

3. Evaluation Criteria • Positional accuracy • Currentness of data • Geocoding • Network analysis & routing • Rich street attributes • Enhanced census boundary files • Traffic count data • What are other organizations doing?

4. Positional Accuracy • Published Accuracy • Visual Comparison with DOQQs • Streams • Comparison • NHD

5. Positional Accuracy • Published Data Accuracy* • TeleAtlas • 60% of population is +/- 8 meter from aerial photography, driven by field crews for confirmation/updates. • 87% of population is +/- 8 meter, not yet driven. • Exceptions = POSACCUR attribute • 0 = normal • 1 = +/- 100m • 2 = +/- 10s of meters • GDT • “Enhanced” areas up to 4-7m. These areas include all major metropolitan areas, all state capitols, several counties and a few entire states. . *from product documentation. Confirmed/updated via email communication

6. Positional Accuracy - DOQQ • Urban • Visual Inspection • TeleAtlas • Streets align with DOQQs and fall within published margin of error. • GDT • Streets align with DOQQs and fall within published margin of error.

7. Positional Accuracy - DOQQ • Rural • Visual Inspection • TeleAtlas & GDT • Depending upon the county, TeleAtlas may have more detail or GDT may have more detail. • In general, both tend to follow Tiger2000.

8. Positional Accuracy - Streams • Streams • The street networks align with the DOQQs, which align well with streams. • GDT comes with a more detailed stream dataset than TeleAtlas. • National Hydrography Dataset is potentially more detailed than either GDT or TeleAtlas.

9. Positional Accuracy - Conclusions • DOQQs • GDT and TeleAtlas are comparable for accuracy. • Streams • GDT has a better water dataset, but NHD is probably a better resource.

10. Currentness of data • GDT • Street Data: • Total 8,500mi of new streets with 421,000 mi of named and addressed streets added in April 2003 version 13.1 • Mileage of street repositioned for accuracy within 12 meters increased 188% since July 2000 release. • Number of named street addressed segments increased 11% over maps released in July 2001 and 19% since maps released in July 2000.

11. Currentness of data • TeleAtlas* • 82% of the US population has been updated by aerial photography to an 8m specification within the last 18 months. • Field survey crews are just behind the photo interpretations (60% complete) & drive the entire network with GPS for more precise updates & corrections. • Remainder of areas are basically TIGER (1999-2000) * Recent information received in email from TeleAtlas dated 8/18/03

12. Geocoding Comparison of GDT, TeleAtlas and Parcel datasets Geocoded 6192 real addresses The addresses are a random sample from a real case study in MD. ESRI Geocoding defaults used: Spelling Sensitivity 80%, Min Score 10%, Min Match Score 60%

13. Network Analysis & Routing • TeleAtlas • Contains routing shapefile • GDT • Does not contain routing information. Dynamap/Routing and Dynamap Highways Routing are two additional datasets available for purchase

14. Richness of Attributes

15. Richness of Attributes

16. Richness of Attributes

17. Richness of Attributes • GDT does not have routing or detailed street attributes, only attributes for geocoding. No relate tables. • GDT has another software package for purchase for routing, transportation, & traffic counts • TeleAtlas includes routing, detailed street information, & geocoding (direction, one ways, intersections, road condition, etc.) with relate tables

18. Census Boundaries - GDT • GDT • PROs • Census boundaries are more detailed than Tiger2000. • Boundaries for split highways digitized in median • CONs • Boundaries not defined by Dynamap 2000 street data • Only two separate shapefiles: • Census Tracts • Census Blocks • Need to purchase Dynamap/Census for more accurate boundaries aligned with street data.

19. Census Boundaries - GDT

20. Census Boundaries - TeleAtlas • TeleAtlas • PROs • Census boundaries are more detailed than Tiger2000. • One shapefile contains a code to extract all political boundaries • Boundaries defined by street data • Also contains Municipality shapefiles • CONs • Boundaries for divided-highways use existing streets, but jump from one side to the other for a jagged boundary.

21. Census Boundaries - TeleAtlas

22. Traffic Count Data Neither TeleAtlas Multinet nor Dynamap/2000 contain traffic counts GDT DOES have another product for NationalTraffic Counts: Dynamap/TrafficCounts

23. What are other organizations doing? -TeleAtlas • USDA - TeleAtlas referred from technical evaluation (RFQ sent to both companies) • They have similar needs from a streets dataset as our GIS users • USDA technical evaluation found TeleAtlas offers more functionality with their dataset than did GDT Dynamap 2000. • National Guard – TeleAtlas • Comments: • Both datasets are comparable for accuracy • TeleAtlas was cheaper • TeleAtlas allowed re-distribution, GDT did not.

24. What are other organizations doing? -GDT • US EPA - Dave Wolf Selected Dynamap/2000 data to support the EPA's Intranet version of Envirofacts. Product purchased because of the currency and accuracy. • US DOT Bureau of Transportation Statistics - Steve Lewis (202)366-9223 Selected Dynamap/Transportation to serve as the standard for all DOT transportation network analysis. Product selected based on our ability to capture and manage change on a national level and our ability to deliver data in SDE format. • US DOT National Highway Traffic Safety Administration - Barry Eisemann (202)366-5367 Selected Dynamap/Transportation to serve as the foundation for the Fatal Accident Vehicle Reporting System. Currently in place in all 50 state data collection centers. Purchased based on the completeness of the national dataset • Federal Reserve Board - Tom Nguyen (202)452-3724 Use Dynamap/2000 for internet based geocoding of HMDA loan applications and display. Selected based on GDT ability capture new growth to enhance geocoding. Source: email communication from GDT

25. Summary Comparing the sample datasets was like comparing apples to oranges. • TeleAtlas’ Multinet contains all of the needed information, except for traffic counts • GDT Dynamap 2000 evaluation data only includes the base streets network. Additional products are available “ala cart”.

26. Summary Based solely on the sample datasets, the positional accuracy and completeness of the datasets are almost equal. However, TeleAtlas includes almost all of the information that our GIS Users need in one product (Multinet) while GDT offers a “menu” of products.