Many cities have adopted minimum parking requirements, but we have relatively poor information about how parking infrastructure has grown.
In this research, using building and roadway growth models, we estimate how parking has grown in Los Angeles County from 1900 to 2010, and how parking infrastructure evolves, affects urban form, and relates to changes in automobile travel.
We find that since 1975, the ratio of residential offstreet parking spaces to automobiles in Los Angeles County is close to 1.0 and the greatest density of parking spaces is in the urban core. Most new growth in parking occurs outside of the core. 14% of incorporated land in Los Angeles County is committed to parking. Uncertainty in our space inventory is attributed to our building growth model, onstreet space length, and the assumption that parking spaces were created as per the requirements.
The continued use of minimum parking requirements is likely to encourage automobile use at a time when metropolitan areas are actively seeking to manage congestion and increase transit use, biking, and walking. Widely discussed ways to reform parking policies may be less than effective if planners do not consider the remaining incentives to auto use created by the existing parking infrastructure. Planners should encourage the conversion of existing parking facilities to alternative uses.