Value Of Travel Time Savings Research Articles

High-speed railway in developing countries: mind the gap -lessons from Morocco-

ABSTRACT Conducted prior to the launch of the High-Speed Railway (HSR) in Morocco, this study aims to be the first research to assess the HSR project through the estimation of the value of travel time savings. We focused on inter-urban routes to assess the HSR project impact. We conducted a Discrete Choice Experiment in the cities impacted (directly or indirectly) by the HSR project, which are Tangier, Kenitra, Rabat, Casablanca and Marrakesh. Our results show that at the sample average points of each mode of transport, the values of travel time savings are approximately 94MAD/h for car users, 27MAD/h for train users and 25MAD/h for bus users. We performed a simulation for the Tangier-Casablanca route and obtained satisfactory results (93MAD/h, 26MAD/h and 24MAD/h, for private car, train, and bus journeys respectively). Finally, our results show that the pricing strategies of the national railway operator (Office National des Chemins de Fer) present a potential risk of eviction, which could counterbalance the positive impact of the time savings.

Assessing automated air-taxis for urban mobility

This paper explores the feasibility and potential implications of automated air-taxis as a new mode of urban transport. By applying flight simulation and operations research, we investigate different questions regarding travel time, travel costs, and transport sustainability. As practical application, we consider the transportation service between the city and the airport, as well as on-demand air-taxi services within the city of Vienna. We compare the air-taxis with gasoline taxis and e-taxis, as they serve analogous transportation needs and cater to a similar clientele. In our effort to assess the feasibility of air-taxis, we aim to answer crucial questions that will influence the future of urban transportation. Our study examines how efficient air-taxis are in reducing travel time and explores their cost dynamics, addressing the affordability for passengers and their value of travel time savings. Additionally, we investigate their environmental impact by looking into energy consumption and CO2 emissions. Through a rigorous analysis of empirical data and simulation outcomes, we aim to provide a comprehensive perspective that informs policy decisions and guides the evolution of urban transportation networks in the years to come.

Urban Air Mobility (UAM): Airport shuttles or city-taxis?

In the last years, Urban Air Mobility (UAM) has been receiving increasing attention and even if the first services are expected to be launched shortly, there is still uncertainty about which type of commercial services (e.g., airport shuttles or city-taxis) will be implemented at an early stage, as well as which price point will be perceived as affordable by travelers. Based on data collected through a large-scale survey campaign in the Milan metropolitan area (Italy), in this paper passengers' value of travel time savings for different UAM services are estimated using advanced discrete choice modeling. Estimated mixed logit models allowed to comparatively analyze the differences between the two potential use cases, i.e., airport shuttle and city-taxi services. Results show a willingness to pay for UAM services from/to airports that is greater (in a range of 44%–57%) than for travelling within the metropolitan area, and greater (in a range of 31%–44%) for business travels than for other purposes, indicating that the most financially sustainable UAM services will potentially be available for airport-shuttle connections from/to central business districts.

Value of travel time savings for leisure trip in autonomous vehicles: Case study from the Tokyo Metropolitan Area

This study estimates the value of travel time savings (VTTSs) in autonomous vehicles (AVs) for leisure trip, using data collected from a stated-choice survey in the Tokyo Metropolitan Area, Japan. The survey was implemented through an internet monitoring program from February to March 2020, collecting 1,224 responses to stated-choice questions from 204 respondents. The survey was designed to request that the respondents choose AV or non-AV under six hypothetical conditions of travel time and cost when they are assumed to be using a car rental service to travel alone for a leisure purpose trip. Simple binary logit models are employed with two types of specifications in the utility function. First, the estimation results of the models without heterogeneity in the utility function showed that the VTTS in AVs is lower than that in non-AVs by approximately 7.3 % on average; however, the reduction of VTTS is not statistically significant. Second, the estimation results of the models incorporating observable heterogeneity into the marginal utility with respect to travel time also revealed that the individual’s preference of in-vehicle multitasking, age, and gender do not significantly affect the reduction of VTTS in AVs. Finally, changes in preference of AV-unique multitasking may affect VTTS, which should be monitored for future updating the VTTS guidelines.

Decomposing mode-specific values of travel time savings with respect to different levels of travel-based multitasking: A revealed preference study

There is ample evidence that the VTTS of public transport (PT) users is lower than that of car drivers and dropped further in recent years. One reason could be the better conditions for multitasking in PT, which improve continuously with the availability of mobile information and communication technologies. While this was addressed in several stated preference studies, revealed preference studies are scarce. None of them estimated the effect of multitasking on the VTTS and how this effect depends on activity types and travel modes. We estimate the effect of multitasking on the VTTS of PT users and car drivers using revealed preference data from a weeklong mobility and activity survey in Austria. Multitasking activities were allocated to two levels depending on whether they can be performed while driving (level 1) or not (level 2). In our two-stage modelling approach, stage 1 predicts the multitasking behaviour in non-chosen modes, while stage 2 uses these predictions to estimate the effect of multitasking on the VTTS using a mode choice model as utility framework. We find that the VTTS of PT users is lower than that of car drivers even without multitasking (5.50 vs. 14.32 €/h) and further drops with different levels of multitasking (3.95 and 3.35 €/h for levels 1 and 2), whereas the VTTS of car drivers drops only insignificantly to 14.05 €/h with level 1multitasking. The results emphasise the importance of good multitasking conditions alongside fast connections for the choice of PT.

Health indicators, mode choice, and trip time-cost trade-offs: Evidence from out-patient trips to health care facilities

This paper analyzes whether health indicators affect the values that out-patient trip-makers place upon their travel times. Data for the analysis is a biennial longitudinal sample from 2011 to 2015, comprising individuals in China 45 years of age and older. For nineteen health factors that characterize health behaviors, disease events, physical mobility, and mental health, the analysis estimates baseline mode-choice models and separate models for respondents with and without a negative health factor present. The study documents increasing trends in travel time sensitivities and values of travel time, and finds that health status affects travel time sensitivities and values of travel time. Problems with physical mobility lower out-patient trip makers' values of travel time, whereas health factors related to non-physical mobility conditions tend to raise values of travel time. The study includes robustness tests and a discussion of endogeneity. The study's findings have implications for older population mode choices, transport and health infrastructure projects focused on providing more access, and for cost-benefit analyses whose benefits include value of travel time savings.

The income elasticity of the value of travel time savings: A meta-analysis

The value of travel time savings (VTTS) is an important concept used in cost-benefit analyses for project appraisals and demand modelling in the transport sector. The relationship between the VTTS and income is particularly important since it underpins how official VTTS recommendations are uplifted over time as incomes grow. The income elasticity of VTTS has been investigated in many empirical studies, exhibiting considerable variation across them. Notably, repeat studies tend to find the lowest implied income effects and meta-analyses the largest income elasticities, with those obtained from cross-sectional inter-personal comparisons somewhere between. This paper aims to explain the VTTS variation in terms of an individual's or household's income level by using the meta-analysis technique. The analysis covers 268 income elasticities of the VTTS extracted from 49 studies conducted from 1968 to 2019 in countries across the globe. The meta-analysis method determines the factors that influence these income elasticity variations. The results of the meta-model highlight that the variation of the income elasticity is explained by several factors, including income levels, the transport mode, personal or household income, inter-temporal or cross-sectional elasticity, journey purpose and year of the survey, shedding light on how the VTTS income elasticity varies across different sources.

Autonomous vehicle impacts on travel-based activity and activity-based travel

This paper undertakes a deep dive into the kinds of activities that individuals are likely to pursue when freed from the task of driving in the fully automated vehicle (AV) era. We refer to such activities as travel-based activities (TBAs) and examine the potential effects of TBA participation on activity-based travel (ABT). Two aggregate ABT characteristics are considered: additional local area travel (ALT) and additional long distance travel (ALDT). TBAs and the two ABTs are jointly modeled in a parsimonious fashion using psycho-social latent constructs, individual characteristics, and built environment (BE) attributes. The data used in this study is drawn from a 2019 “emerging mobility” survey administered in the Austin, Texas metropolitan area by the research group. Our study indicates that “productive use of time” is not necessarily always tied with activities such as work and study; rather, being able to partake in relatively chill activities (such as sleeping, relaxing, and gazing out the window) is also considered as good use of time. This suggests caution in the interpretation of what are traditionally referred to as “productive” activities and also a need for scholarly restraint in the use of the label “multitasking” to exclusively refer to non-passive activities. We suggest that the field move away from subjective/ambiguous terms such as multitasking and “productive” activities, and adopt the more neutral label of “travel-based activity”. The results also support the notion that the option of opening up travel to pursue work/study activities may itself be engendering stress in individuals; that is, as the option to pursue “non-chill” activities increases in an AV environment, that itself may produce angst in individuals and lead to less enjoyment in travel. This also highlights a need to examine TBAs in the broader context of emotional well-being and quality of life. Indeed, AVs may further erode into our time of tuning-out from the “chatter” of routine life and make it less possible to partake in “calm and mindless” activities. Finally, our study cautions against the use of simple and uniform (across individuals) value of travel time savings (VTTS) factor modifications to study AV impacts on ABT.

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.

Valuation of unpaid time savings on toll roads using transport model

A well-known problem known worldwide is that demand on toll roads gets overestimated when traffic intensity is being predicted. This leads to inefficient operation of highways and loss of profit. Therefore, it is important to accurately predict flexible demand when designing a toll road. Flexibility of demand depends on VTTS and is usually determined by public polls.Purpose: the purpose of this article is to develop a method for estimating the amount of unpaid travel time savings on toll roads. The value of travel time savings is calculated on basis of a sociological survey. The amount of travel time savings is estimated on basis of objective data acquired, i.e. information about actual motorists’ trips in St. Petersburg on both free and paid roads. The value of travel time savings allows to realistically tune the parameters of a transport model for agents planning their trips. As a result, the transport model allows to estimate the total amount of time saved daily with a toll road.The cost of the travel time savings for St. Petersburg drivers as well as the total amount of unpaid time savings on the toll road is calculated. It turned out that the price of the time saved by motorists on most routes did not correspond to the established road fares. The research results show the potential to set up toll road fares based on the actual cost of the saved travel time, which could optimize toll road revenue.

Mobility-impaired people’s preferences for a specialized paratransit service as BRT’s feeder: The role of autonomy, relatedness, and competence

Transportation is a very important element in the well-being of mobility-impaired people. However, people with disabilities often struggle to access transportation services at all, especially if they live in mountain areas. This study is aimed at better understanding the main factors that affect the preferences for a new specialized paratransit service as BRT’s feeder to serve the portion of the trip that mobility-impaired people cannot manage. We hypothesized that in addition to some observable attributes of the transportation services, such as time and travel cost, mobility-impaired people’s preferences for a specialized paratransit service as BRT’s feeder could be better explained by using a hybrid discrete choice model based on the Self-Determination Theory (SDT). We gathered responses through a stated-preference survey (N = 350), in which respondents faced a series of choice situations among three BRT feeder alternatives: bus, cable car and a new specialized service. We also obtained indicator ratings through a basic psychological needs satisfaction scale to identify the latent variables in relation to the SDT. Modeling results supported our hypothesis that the preferences of mobility-impaired people are better explained by considering the three innate psychological needs. We found empirical evidence linking the components of the SDT, i.e. Autonomy, Relatedness, and Competence, with preferences for the specialized transportation service as BRT’s feeder in the study context. The multipliers of values of time savings derived from the model showed that mobility-impaired people place access time four times more important than travel time. We accounted for the heterogeneity in value of travel time savings and found that the greater the autonomy in mobility-impaired people the greater their sensitivity to the specialized transportation service’s fare. We concluded that Autonomy, Relatedness, and Competence play an important role in the preferences of mobility-impaired people. Autonomy is a determining factor in perception of alternative fares. Competence motivates mobility-impaired people to use the specialized paratransit service as BRT’s feeder, while Relatedness motivates mobility-impaired people to use the same transportation alternatives used by others.

Transit “Pass-Through” Lanes at Freeway Interchanges: A Life-Cycle Evaluation Methodology

Transit “pass-through” lanes provide transit vehicle priority at freeway interchanges. “Pass-through” lanes allow a transit vehicle to exit the freeway at an interchange, cross straight through the intersecting arterial road, and re-enter the freeway. This treatment allows transit vehicles to bypass congestion on the mainline between the beginning of the off-ramp and the end of the on-ramp.This paper outlines a methodology to evaluate if transit “pass-through” lanes are economically justified at a given interchange and provides a method for prioritizing candidate locations. The methodology provides an objective and consistent decision making method, reduces the effort required for practitioners to assess the need for “pass-through” treatment at a given interchange, and helps ensure that limited resources are directed towards interchanges that are expected to experience the greatest benefit per dollar spent.The proposed methodology is based on an analytical approach that compares the value of travel time savings (for passengers and transit vehicles) with the construction and maintenance costs of the transit “pass-through” lane treatment.

A tale of two modes: Who will use single user and shared autonomous vehicles

The two most traditional and conventional transportation modes, private vehicles, and public transit, may be disrupted due to the advent of shared autonomous vehicles (SAVs), which can offer affordable on-demand mobility solutions leading to a transformed transportation system. However, little is known about the attributes affecting mode choice decisions and the impacts of the emergence of SAVs on travel behavior. A stated preference survey consisting of choice experiments, distributed online in October and November 2017 to residents of the Chicago-Naperville-Elgin, IL-IN-WI metropolitan statistical area, is used to determine the perceived impacts that SAVs may have on mode choice decisions and the corresponding value of travel time savings. Based on a representative sample (in terms of age and gender) of 400 responses, random parameter (mixed) logit models are developed to investigate the factors that affect mode choice decisions in short- and long-term scenarios. Value of travel time savings (VTTS) is calculated using the marginal rate of substitution derived from the mixed logit models. The results indicate that the option of sharing the AV ride is not as preferable as single occupant AVs across all market segments, which may challenge the benefits that this emerging technology can bring to shared transportation modes. Further, it was found that VTTS is lower for SAVs compared to single occupancy AVs regardless of the time horizon.

Analyzing simple work time and commute time tradeoffs for insights into components of the value of travel time savings

Tradeoffs between work, travel, and leisure have been made explicit through the value of travel time savings (VTTS) and its components, including the values of time assigned to work and to travel. A few studies have recently been able to empirically decompose these dimensions of VTTS, but they usually rely on costly multiday activity–travel–expenditure diaries and surveys. In this paper, we use panel mixed logit modeling to analyze a very simple and easy-to-administer set of choices (work time and commute time tradeoffs) that allows us to quantify some (but certainly not all) aspects of these VTTS components: specifically, we find the signs (positive or negative) and relative magnitude of the marginal utilities of work time and commute travel time. In contrast to previous research, our results imply that commuting seems to be more onerous than working (the marginal utility of travel time is more negative than the marginal utility of work time) on average, except not so for walk and bicycle commuters. We also find differences related to age, income, education, travel satisfaction, and commute preferences.

Value of Travel Time Savings of Autonomous Vehicle Commuters: A Segmented Valuation for Local and Inter-City Travel

Value of Travel Time Savings of Autonomous Vehicle Commuters: A Segmented Valuation for Local and Inter-City Travel

Impact of COVID-19 restrictions on mode use and mode captivity the city of Santo Domingo in Latin America

This paper explores transportation mode choice patterns of a population in Latin America before and during the COVID-19 pandemic based on survey data from the city of Santo Domingo (Dominican Republic). An online survey consisting of two waves was conducted between April and June 2020 among randomly chosen transport system users. The survey consisted of both a stated choice experiment, revealed preference, andpsychometric indicators. Hybrid choice models were developed and included two latent variables (1) satisfaction with public transport and (2) the response to COVID-19. The results indicate that there is a strong habit of private vehicle use in the Dominican population. The main deterrents for public transport use are limited capacity and reduced safety (including regarding social distancing). The findings particularly highlight the success of the metro as a public transport mode in the city of Santo Domingo. Both cost and time are significant factors in mode choice, before and during the pandemic, but more so for OMSA bus use than for metro use. One of the conclusions from this study is that ignorin covid-related latent effects on public transport service during the pandemic may yield biased (lower) estimations of Value of Travel Time Savings. Finally, the results also show that mode captivity for public transport users plays an important role during the pandemic. These users have no access to alternative transportation and are obliged to continue using public transport. This implies that governments would be wise to urge transport operators not to reduce capacity and frequency during the pandemic.

On the quality requirements of demand prediction for dynamic public transport

As Public Transport (PT) becomes more dynamic and demand-responsive, it increasingly depends on predictions of transport demand. But how accurate need such predictions be for effective PT operation? We address this question through an experimental case study of PT trips in Metropolitan Copenhagen, Denmark, which we conduct independently of any specific prediction models. First, we simulate errors in demand prediction through unbiased noise distributions that vary considerably in shape. Using the noisy predictions, we then simulate and optimize demand-responsive PT fleets via a linear programming formulation and measure their performance. Our results suggest that the optimized performance is mainly affected by the skew of the noise distribution and the presence of infrequently large prediction errors. In particular, the optimized performance can improve under non-Gaussian vs. Gaussian noise. We also find that dynamic routing could reduce trip time by at least 23% vs. static routing. This reduction is estimated at 809,000 €/year in terms of Value of Travel Time Savings for the case study.

Public acceptance of electric roadways: The case of Los Angeles, California

Dynamic charging has the potential to overcome the barriers to electric vehicle (EV) adoption by converting road segments into powered lanes (electric roadways or ERs). This paper focuses on examining public acceptance by determining the factors that affect the short-term and long-term intention to purchase an EV and drive on ERs; identifying the clusters of the technology acceptance; and assessing the value of travel time savings (VTTS) for driving on ERs, in general, and for different clusters. A survey was conducted in Los Angeles, California and distributed online, gathering 600 responses. The results showed that respondents’ innovativeness, lifestyle and environmental consciousness significantly affect the intention to drive on ERs in the short- and long-run. Public acceptance, in general, seems to be related to charging patterns, safety of commute route, and safety concerns for ERs, among other factors, and depends on the implementation time of the technology. Higher VTTS were found for electrified lanes exclusive for EVs on interstate and arterial roads. People who were classified as positive toward ERs had higher VTTS for ERs followed by those who were neutral and those who were concerned about ERs. This paper can help policymakers and transport operators devise strategies to accelerate EV adoption by appropriately implementing the ER technology.

Impact of trust and travel experiences on the value of travel time savings for autonomous driving

Autonomous driving is expected to strongly influence the value of travel time savings (VTTS) which is crucial for the assessment of the impact of automated vehicles (AVs). However, no consensus has been reached yet about the size and direction of the effect of AVs on VTTS. This high uncertainty around the VTTS is most likely due to high heterogeneity in preferences for travel time. Our hypothesis is that a key role in the heterogeneity of the VTTS for AVs is played by psychological factors. We focus in particular on Travel Experiences (besides individual preference for activities conducted during travelling) and Trust in travel time preferences for AVs. For this purpose, an online survey with a stated choice experiment and psychometric scales was conducted. Besides currently available transport modes, also a privately-owned AV (PAV) and a shared AV (SAV) were included in the choice sets. The data was analysed using a hybrid choice model. T-test and confidence intervals of the estimated VTTS are computed to assess if the VTTS are statistically significant and statistically different among user groups. Results confirm that both psychological factors have significant positive effect on VTTS for AVs. Gender, age, level of education and experience with similar systems were found to affect the VTTS directly and indirectly through their impact on the individual attitudes. Significant differences are found among some potential user groups, in particular in terms of trust to technology and anticipated travel experiences. For example, men are found to trust the technology more than women and also to have potentially higher technology affinity. However, our results show that they also perceive higher marginal disutility for travel time in both PAV and SAV. A comparison between a mixed logit model and the hybrid choice model reveals that capturing the indirect effect of the socio-economic characteristics of individuals through the effect of these factors on attitudes allows differentiating between the VTTS for different user groups. Lastly, implications for policy and technology deployment strategies are discussed based on the findings.

The role of unpaid domestic work in explaining the gender gap in the (monetary) value of leisure

The value of travel time savings (VTTS) representing the willingness to pay to reduce travel time, consists of two components: the value of liberating time [equal to the value of leisure (VoL)] and the value of time assigned to travel (VTAT), representing the travel conditions of a trip. Their relative values indicate which dimension to emphasize when investing in transport: speed or comfort. In this paper, we formulate and estimate a framework aimed at the improvement in the estimation of the VoL. By introducing a novel treatment of time assigned to domestic work, we consider that unpaid labor should be assigned a wage rate as a measure of the expenses avoided when assigning time to those chores. We use state-of-the-art data on time use and expenses as well as online data on gig workers collected in Austria, and apply the time-use and expenditure model of Jara-Diaz et al. (Transp Res Part B 42(10):946–957, 2008). The wage rates for paid and unpaid work were combined to re-formulate the budget constraint, which affected women more than men due to the higher involvement of the former in domestic activities. Compared against the original estimation, the VoL changed from €10/h for men and €6/h for women to €9/h for both genders, which in turn yields a larger average VTAT, which becomes positive for public transport. As a conclusion, the novel treatment of domestic labor contributes to closing the gap in the VoL between genders and highlights the power of unveiling the components behind the VTTS. The empirical findings imply that investments in travel time reductions rather than in comfort should be prioritized, given the very good conditions of public transport in Austria.