NHS Routes: Seattle's National Highway System Road Network

NHS Routes are geospatial data maintained by the Seattle Department of Transportation, displaying the city's National Highway System network. The dataset is updated daily by the City of Seattle and was last refreshed on March 22, 2026. It is available in multiple formats including CSV, JSON, and KML for analysis and mapping.

Use Cases

• Map and visualize the National Highway System road network in Seattle based on the geospatial route data.
• Perform network analysis for transportation planning based on the maintained NHS routes.
• Integrate road network data into urban mobility models based on the daily updated feature class.
• Create transportation-focused web applications using the available GeoJSON or KML formats.

Strengths

• Data is updated daily, ensuring high recency.
• Available in multiple interoperable formats including CSV, JSON, KML, and GeoPackage.
• Geospatial data is explicitly maintained by a municipal transportation department (SDOT).

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count and dataset size are unknown, which may limit suitability assessment.
• Description metadata is limited; actual data quality requires manual inspection after download.

Provenance

Source

Seattle Department of Transportation (SDOT)

Collection Method

Maintained by the municipal transportation department.

Time Range

Current, with daily updates.

Freshness

Daily refresh cycle; last updated 2026-03-22.

Geography

City of Seattle, Washington, USA.