Composition of Vehicle Occupancy for Journey-to-Work Trips

Abstract

Ridesharing serves to mitigate pollution and congestion with minimal investment of public capital while also increasing the efficiency of the transportation system. This research addresses the gaps in the literature on the structure and formation of ridesharing by identifying individual, household, and physical-environment characteristics that correspond with an individual's choice to rideshare instead of drive alone. For a fuller understanding of ridesharing behavior, there first must be a better understanding of who is in the vehicle, not just how many. A distinction is made between intrahousehold (internal) and interhousehold (external) ridesharing. With the Vermont add-on sample of the 2009 National Household Travel Survey, a multinomial logit model and nested logit model were developed to examine the determinants of ridesharing. The analysis in this research stresses the importance of the way ridesharing behavior is extracted from survey data. Further, a new method for calculating household vehicle availability is presented; the method places less importance on drivers who are not full-time workers. Results indicate that employment density, longer distance traveled to work, and working in a small urban area have positive influences on the likelihood of ridesharing. Higher vehicle availability in the household, age, sex (male), and a longer time spent per trip on the journey to work were all found to influence the propensity to rideshare negatively. Cost of travel does not significantly affect ridesharing.

Rideshare mode potential in non-metropolitan areas of the northeastern United States

“…The model results suggest that females who are younger than 55 (-0.9374 + 0.7469 + 0.7347 = 0.5442) are more likely to rideshare, if all else is equal, than older males (i.e., the reference group), but less likely to rideshare than younger males (0.7347) and older females (0.7469). This finding is consistent with previous research that found females and younger commuters to be more likely to rideshare (Belz and Lee 2012).…”

“…All of these variables were found to positively explain rideshare behavior. In particular, having fewer vehicles than drivers appears to be the largest influence on those who used rideshare in their most recent home-to-work journey, which is consistent with the literature (Belz andLee 2012, Hartgen 1977). Household income was not found to be related to rideshare, but it is highly correlated with educational level and age.…”

“…Educational attainment has been suggested to play a larger role than other socio-demographic factors (Hartgen 1977). Belz and Lee (2012) find that individuals over the age of 40 years are less likely to rideshare compared to the younger population, with a preference for intra-household ridesharing over inter-household ridesharing. They also show ridesharing is more likely for females.…”

“…Carpool users tend to travel farther than single-occupancy vehicle drivers (Teal 1987), and one study suggests that carpooling becomes appealing at a travel distance of 10 miles (Tsao and Lin 1999). Belz and Lee (2012) showed a slightly greater tendency toward interhousehold ridesharing than intra-household ridesharing as the distance to work increases.…”

“…Others (Belz and Lee 2012;Hartgen 1977) suggest that vehicle availability is an important determinant. Educational attainment has been suggested to play a larger role than other socio-demographic factors (Hartgen 1977).…”