National Highway System (NHS)

NHS Coordinators:
Eric Wong – HPMS Branch Chief

Jessica Wang – NHS Coordinator


The National Highway System consists of roadways important to the nation’s economy, defense, and mobility. The National Highway System (NHS) includes the following subsystems of roadways (note that a specific highway route may be on more than one subsystem).

Interstate: The Eisenhower Interstate System of highways retains its separate identity within the NHS. 

Other Principal Arterials: These are highways in rural and urban areas which provide access between an arterial and a major port, airport, public transportation facility, or other intermodal transportation facility.

Strategic Highway Network (STRAHNET): This is a network of highways which are important to the United States' strategic defense policy and which provide defense access, continuity and emergency capabilities for defense purposes.

Major Strategic Highway Network Connectors: These are highways which provide access between major military installations and highways which are part of the Strategic Highway Network.

Intermodal Connectors: These highways provide access between major intermodal facilities and the other four subsystems making up the National Highway System. 


  1. Caltrans Web Map
  2. FHWA-NHS Web Map
  3. NHS Modification Procedures
  4. Code of Federal Regulations 23 CFR 470
  5. HPMS Field Manual
  6. Caltrans NHS GIS Dataset