Value of travel time savings of autonomous vehicle commuters: a segmented valuation for local and inter-city travel

ABSTRACT

In this study we aim to identify how the adoption of autonomous vehicles (AVs) affects the value of travel time savings (VOTTS) for commuting trips under different trip distance scenarios (local and inter-city travel). Using a stated preference survey administered to Korean commuters in 2019, two multinomial logit (MNL) mode choice models are developed. These models are stratified by trip length and include four alternatives: AV with a manual driving option (AVMD), AV with a self-driving option (AVSD), shared AV (SAV), and public transit (PT). The results show that the value of in-vehicle travel time savings for AVSD (on average, $7.61/hr) is lower than for the other two AV modes (AVMD = $10.26/hr, SAV = $13.67/hr). It suggests that travelers tend to pay less to reduce travel time while using a private hands-free mode because it allows travelers to use their travel time more productively and/or relieve stress for driving. In addition, changes in the VOTTS for each mode vary by trip length. As travel distance increases, VOTTS for shared modes (SAV and PT) tends to decrease. The value of in-vehicle travel time for SAV in the local travel scenario is the highest among the four modes but is considerably lower than that in the inter-city scenario. These differences suggest that travelers require a certain amount of time to fully use their in-vehicle time, highlighting the importance of trip length when determining the VOTTS. Interestingly, the VOTTS for PT is lower than three AV modes, implying that it might be too early to expect substantial reduction in the VOTTS for AVs due to potential risks of accidents, unfamiliarity with AVs, or immature technology of AVs.

Highlights

• Likelihood of choosing autonomous vehicles is modelled based on trip length.

• Changes in value of travel time savings for each mode vary by trip length.

• Value of travel time savings for public transit is lower than autonomous vehicles.

• Self-driving vehicles have a low value of travel time savings than other modes.

• People need a certain amount of time to fully perform activities while traveling.

KEYWORDS:

• Autonomous vehicles
• value of travel time savings
• mode choice
• stated preference
• multinomial logit model

Acknowledgement

This work is supported by the Korea Agency for Infrastructure Technology Advancement (KAIA) grant funded by the Ministry of Land, Infrastructure and Transport (Grant 21AMDP-C160881-01). It was presented in the poster session at the 100th TRB Annual Meeting and has been updated based on comments from the poster session.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

Sungtaek Choi: Conceptualization, Methodology, Analysis, Writing & Draft Review. Daejin Kim.: Methodology, Data processing, Resources, Writing & Draft Review. Joonho Ko: Funding Acquisition, Conceptualization, Supervision, Writing – Review & Editing. Jonghan Park: Data processing, Validation, Writing. Yongseok Ko: Funding Acquisition, Supervision, Writing – Review & Editing.

Notes

1 As one of anonymous reviewers pointed out, the sample size and its composition do not represent population characteristics perfectly. The mode shares presented in this study also do not represent the market shares in the entire SMA. However, we believe the sample can reflect travelers’ behavior in the study area which allows us to understand the skeleton of future mode shares and take a glimpse into future of AV travel based on that (1) survey was conducted by the professional consulting company who secure reliable panel members, and (2) the sample distribution was intentionally designed to reflect population.

Additional information

Funding

This work was supported by the Korea Agency for Infrastructure Technology Advancement (KAIA) grant funded by the Ministry of Land, Infrastructure and Transport: [Grant Number 21AMDP-C160881-01].