Variable	Potential Default Value	Notes and Sources	Specific to California
Growth Factor (G)	1.0	See Table 1 and proceeding discussion.	No
Trip Type Factor (T)	0.506	Default is based on the combined share (49.4%) of bicycle trips made for “vacation” (2.1%) or “other social or recreational” (47.3%) purposes, taken from the 2009 National Household Travel Survey in the United States. Default is the percentage of all other trips, calculated as 1–0.494 (= 0.506); however, this article covers why this factor might lead to a conservative projection.	No, but specific to the US
Auto Substitution Factor (A)	0.1	Matute et al. (2016); Monsere et al. (2014); Thakuriah et al. (2012).	No
Carpool Factor (L)	1/1.15	Reciprocal of average vehicle occupancy rate (average number of people per auto) used by California Department of Transportation (1.15) (CA Department of Transportation, 2016).	Yes
Trip Length Factor (L)	2.4	Average bicycle trip length (kilometers) across all trip purposes, as estimated by 2010–2012 California Household Travel Survey (CA Department of Transportation, 2013).	Yes