2018

Often, discussion of sustainable mobility transitions will flow from a constrained view of consumer perceptions and cultural meanings. From this limited viewpoint, an alternative mobility paradigm needs only to replicate these functions in a way that is either similar or better than the status quo in order to succeed. In this paper, we argue that Automobility is far more complex than a functional viewpoint allows.  We introduce a framework to facilitate discussion of the broader complexity of the meanings of Automobility in modern society, which holds important implications for considerations regarding alternative mobility forms and policy changes.  Passenger vehicles can fulfill private functional roles such as making drivers feeling safe and protected (cocooning and fortressing) or providing an opportunity to work (mobile digital office).  They can fulfill private symbolic roles such as signifying gender identity (masculinity and femininity) or social status (class).  They can fulfill societal functional roles such as climate change mitigation (environmental stewardship) or spatial reorganization (suburbanization), as well as societal symbolic roles such as self-sufficiency (a message to oil cartels) and innovation (a message to automotive manufacturers).  The article connects this interpretive flexibility of the automobile to ongoing academic debates over the role of “culture” and cars and policy debates over how to incentivize more sustainable forms of mobility and transport.  We then use these frames to aid a brief discussion of different viewpoints of mobility transitions, namely electric mobility, automation and car sharing, as well as the policies involved in making such a transition.

In this paper, we investigate the factors that limit or encourage the adoption and frequency of the use of ride-hailing/on-demand ride services such as Uber and Lyft in California, and the potential impacts that these services have on other components of travel behavior including vehicle ownership and the use of other means of transportation. In the study, we use data collected as part of a bigger research project that focuses on the travel behavior of millennials and members of the preceding Generation X. We find that millennials are more likely to adopt on-demand ride services and they tend to use the services more frequently. Uber/Lyft users are more likely to be affected by attributes such as waiting time and the easier way to call a ride for Uber/Lyft compared to hailing a taxi. Both users and non-user highly rate the preference to own and use their own vehicle as the strongest limiting factor to the adoption of these technology-based services. This is more true among non-users and infrequent riders who use these services less than once a month. With respect to the impacts of on-demand ride services on the use of other means of transportation, the use of these services tends to reduce the amount of driving made by both frequent and non-frequent users. It also substitutes for some trips that would have otherwise been made by transit or active modes: the substitution effect is stronger among frequent users, those who live in zero-/lower-vehicle households and those who are more multimodal.

Carpooling has potentials as sustainable school commute mode along with other viable transportation options.  It can reduce the negative externalities associated with single occupancy vehicles such as traffic congestion, fuel consumption, and air pollution. Unfortunately, our knowledge of carpooling as school travel mode is very limited. So, the purpose of this paper is to fill this gap. Using multinomial logit model, we analyze data from the 2012 California Household Travel Survey to assess the effects of various factors such as household characteristics, parental characteristics, spatial variables and motivational factors on the choice of carpooling over the car as school mode. We find that households with higher number of 9^th grade to 12^th grade school going children and dual earner parents are more likely to use carpooling as their children’s school mode. Parental characteristics are also important as households with young, female or immigrant household head are more likely to allow their children to carpool to school. Results of spatial variables suggest that households living in the neighborhoods with higher number of school going children are more likely to use carpooling. Distance from home to school is also positively associated with carpooling. Moreover, motivational factor is an important determinant of carpooling to school. The empirical evidence presented in this study provides useful insight to identify potential target groups of carpooling, which will eventually help the concerned authorities to take necessary actions in school travel demand management programs to promote the use of this travel mode.

Problem: How school location impacts children’s air pollution exposure and their ability to walk and bike to school has been a growing policy issue. Smart growth advocates encourage districts to locate schools in “walkable” locations, often near high-volume roadways while health professionals emphasize the importance of minimizing exposure to high levels of air pollution and distance schools from major roads. As states consider or implement laws to site schools away from high-volume roadways, such policies can lead to school locations disconnected from neighborhoods and accessible only by motorized transport modes.

Research Strategy and Findings: This study analyzes children’s air pollution exposure across an average school day, analyzing variation across roadway characteristics, local school and home environment, and mode choice for school commute. This research compares daily average exposures for children walking to a local school in a high-traffic area versus exposures if they were required to be bussed or driven to a distant, “greener” school located in a low-traffic environment. Daily average exposures to air pollution were estimated across an average school day (AM Commute, Unload, School Day, Load, PM Commute). The analysis also assesses how pollution exposure can be mitigated through clean school bus technology, improved HVAC systems, and no-idling policies. Bussing children from a high-traffic neighborhood to a distant school in a low-traffic environment resulted in average daily exposures from 2 to 4 times higher than children walking to their local school.

Takeaway for Practice: Our simulated school siting policy assessment found that bussing children to a distant school in a “cleaner” air quality school site did not reduce average daily personal exposure of children who would otherwise walk or be driven/bussed to their local school in a “dirtier” air quality site. Mitigation measures like a clean bus fleet greatly reduce exposures for children bussing longer distances to a distant school while school HVAC improvements in a heavy-diesel/heavy-traffic school environment yield more conservative reductions.

Keywords: school commutes; air pollution; near-roadway exposures; school siting; pollution mitigation strategies