The Hazardous Liquids Pipeline System is marked by a recent increase in new pipeline installations. Plot 1 presents the most recent Hazardous Liquids mileage data from PHMSA’s By-Decade Inventory. Plot 2 takes this same data and presents the changes to mileage since 2010. The numbers on each side of the area plot denote each decade’s 2010 and 2021 mileage. This chart displays the relative stability of pipeline mileage installed before 2010 and the rapid increase of pipelines installed since then. This point on broader system age composition is further explored in Plot 3, where post- and pre-1970s pipelines are compared, showing a steady movement towards a modernized pipeline system. The incident rates of these pipelines are further examined in our analysis of Incident Rates by Age.
