HPMS Median

The Idaho Transportation Department's (ITD) Roads and Highways Road Network Linear Referencing System (LRS) HPMS median event polyline feature class identifies the type of median separating opposing lanes of traffic along divided highways. Medians improve safety and operations by reducing head-on collisions, minimizing interference from opposing traffic, and providing space for recovery, emergency stops, and potential future lanes. This information is collected from roadway design plans, construction as-built documents, and ITD’s roadway inventory systems in accordance with FHWA HPMS Field Manual coding guidance. Each median is classified by physical type and barrier characteristics. Medians may include unprotected areas, curbed separators, or positive barriers that prevent vehicle crossover. Optional sub-codes describe the rigidity of barrier types (flexible, semi-rigid, or rigid) when that level of detail is available. The dataset supports roadway safety evaluation, network inventory, and performance reporting. It is maintained and updated annually as part of ITD’s Highway Performance Monitoring System (HPMS) submission to the Federal Highway Administration (FHWA). This layer is an export from Roads and Highways that represents only the active records within the LRS. These are current “working” records. For the static, published data, please see the records stored at: https://www.fhwa.dot.gov/policyinformation/hpms.cfm This content item is a sub-layer of the Highway Performance Monitoring System (HPMS) authoritative feature layer. Metadata