Another important policy tool to achieve TDM objectives has been the creation and expansion of commuter benefits—although the types and levels of these benefits has varied across both modes and time (Potter et al. 2006; TCRP 2003; EPA 2007; IRS 2013). Free car parking, however, generally continues to be the most prevalent type of benefit offered to commuters; only about 5 percent of auto commuters pay for parking in the U.S., and commuters, on average, avoid direct payment of the majority of actual parking costs (Wachs 1990; Shoup 2005; TCRP
2005; FHWA 2012a).