Study of Multi-Day Storage Patterns for Gasoline-Fueled Vehicles in the South Coast Air Basin

摘要

Prolonged vehicle non-usage lasting 24 hours or longer contributes to overloading the vapor-trapping canister and results in excess evaporative emissions. Critical factors in determining such evaporative emissions are the duration and frequency of multi-day vehicle storage. To quantify these critical factors for all gasoline-fueled vehicles in the South Coast Air Basin, the following three vehicle storage surveys were designed and implemented: household survey for privately-owned vehicles; business vehicle survey for commercially-owned vehicles; and facility survey for new pre-registered vehicles and used vehicles, which are temporarily dislocated from vehicles' owners' residences. The surveys have revealed that, of the basinwide population of 8.1 million privately-owned vehicles, there are about 2.1 million (25%) vehicles daily experiencing multi-day non-use. For the estimated population of 374,000 commercially-owned vehicles in the basin, there are 137,000 (37%) vehicles daily experiencing multi-day non-use. Of these privately- and commercially-owned vehicles, about 7% are at vehicle holding facilities such as auto-repair shops and parking lots. In addition to these vehicles in circulation, there are 154,000 new, pre-registered vehicles in non-use at new car preparation lots and vehicle dealers.