==== Company/Workplace characteristics ====
Levels of ridership increase more when parking subsidies are decreased rather than when ridership is promoted through subsidies.
==== Income and Auto ownership ====
Individuals households that have less than 1 automobile per person are more likely to rideshare.
Ridership decreases with gains in personal income and auto ownership. Ridesharing trips take more time than single use trip, and time is a finite resource, so those that have a vehicle and put a premium on saved time from single occupancy are more likely to drive alone.
==== Distance ====
Ridesharing increases as communiting distance increases. According to National Personal Transportation Survey data, 14.2% of commuters carpool during the trip shorter than 5 miles but 34.4% carpool at distances over 25 miles.
==== Location ====
Ridesharing and public transit use increases near Central Business Districts (CBD) due to several reasons: 1. commutes are long and traffic is generally heavy to CBD. 2. Individuals are more likely to face parking fees in CBD 3. Public transit is more convenient and available in CBD.