Discrepancies in the spatial extent of common GIS highway networks. Issue 3 (17th March 2021)

• Record Type: Journal Article
• Authors: Weber, Joe
• Is Part Of: Transactions in GIS. Volume 25:Issue 3(2021)
• Page Start: 1565
• Page End: 1576
• Publication Date: 2021-03-17
• Subjects: Geographic information systems -- Periodicals; 910.285
• DOI: 10.1111/tgis.12743
• Languages: English
• ISSNs: 1361-1682

Abstract

Abstract: The Federal Highway Administration's Highway Performance Monitoring System (HPMS) and the U.S. Census Bureau's TIGER geospatial database are relied on by countless professionals, but the two databases differ by 6.9 million km (4.3 million miles), a discrepancy greater than the Federal Highway Administration's national total of 6.6 million km (4.1 million miles). While there are several methodological reasons why a GIS network will give different answers from the HPMS, these cannot explain a difference of this magnitude. The difference exists because TIGER was based on roads shown on USGS topographic maps, the majority of which are not considered public highways today. This overestimate of highway extent can affect a range of network operations in GIS. There is, however, reason to consider TIGER's overestimate an underestimate of the actual extent of roads in the country, as well as questioning which roads should be included in a study.