Information regarding the geometrics of the roadway segment is typically obtained from field visits, as-builts, survey files, the agency’s GIS database, or online maps. TxDOT’s Statewide Planning Map and Open Data Portal are good sources for finding information on bridge crossings, vertical clearances, shoulder widths, and other important roadway-related elements. When collecting information from online maps, it is crucial to check the date of the aerial and verify it is not outdated. Field verification of geometry may be necessary depending on the date of the aerial. See

Appendix H, Section 1 – External References (Reference 4)

for a link to the Statewide Planning Map

and Appendix H, Section 1 – External References (Reference 5)

for a link to the Open Portal website.