Gendered immobility: influence of social roles and local context on mobility decisions in Pakistan

This paper examines the instances of one-day immobility in Pakistan and reports its socio-demographic determinants using the nationally representative dataset of the 2007 Pakistan Time Use Survey. Of 37,830 time diary respondents, nearly 30% did not report travel during the diary day. Homemakers and those out of the workforce were more likely to be immobile than employed or student respondents. Immobility rates were very high among women (55%) as compared to men (4%). Among women, those between 20 and 34 years of age, married, with children, having better education, dependent on other household members and those living in higher income households were more likely to be immobile. The excessive gender nature of immobility seems to be triggered by a gender-based sociocultural environment, which restricts female mobility due to family honor concerns. Other than this, those living in the provinces of Sindh and Khyber Pakhtunkhwa or in urban areas were more likely to be immobile than those living in Punjab and Sindh provinces or in rural areas. The significant geographic effect at broader spatial scale is caused by the demographic structure as well as due to differences in the social and cultural context of these areas. Finally, questions regarding the measurement of immobility and the potential implications of increased female immobility are discussed.     

Weekly activity-travel behaviour in rural Northern Ireland: differences by context and socio-demographic

Despite a wide variation in access to goods and services between rural areas, common policy interventions are often proposed in Northern Ireland. Questions remain as to the level and form of policy differentiation that is required, if any, both within and between different rural areas. This issue is investigated in this paper through the analysis of activity-travel patterns of individuals living in two rural areas with different levels of area accessibility and area mobility. Three focus groups, 299 questionnaires and 89 activity-travel diaries for 7 days were collected for individuals from these areas. Regression analyses were employed to explore the degree to which different factors influence activity-travel behaviour. The results indicate that individuals from rural areas with a higher level of accessibility are more integrated within their local community and as a result, are potentially less at risk of being excluded from society due to immobility. Differences, however, were also found between different groups within an area (e.g. non-car owning individuals who were more reliant on walking, and low-income individuals who made trips of a shorter distance). Based on the study findings and a review of existing policies, this research highlights the need to tailor policy responses to reflect the particular sets of circumstances exhibited in different areas.     

Young people and the private car: A love-hate relationship

Urban mobility is one of the main concerns of the public authorities in developed countries. In France, household travel surveys are conducted every ten years in major cities to gather weekday mobility data. They enable decision-makers to better understand travel patterns, their change and their determinants, in order to adapt transport infrastructures to the population′s needs. While the automobile has allowed the level of mobility to increase since 1950, an unexpected finding has emerged from recent surveys in most developed countries, namely that there has been a marked decline in car use. Analyses show that this trend is mainly because young adults (18–34 years old) are less likely to acquire a driver′s license. This paper tries to better understand the decrease in the rate of driver′s license holding among young adults in the Lyon conurbation and to quantify the impact of the main explanatory factors in a temporal perspective. It also aims to analyze the consequences of this trend on private car use as a driver for daily trips. It quantifies the influence of economic, socio-demographic and spatial factors on driver ′ s license holding and car use by considering the responses to the last three household travels surveys conducted in the Lyon conurbation area (1995, 2006 and 2015). The temporal dimension allows us to highlight a change in the relationship between young adults and the private car in the French context.     

Estimating potential increases in travel with autonomous vehicles for the non-driving,elderly and people with travel-restrictive medical conditions

Automated vehicles represent a technology that promises to increase mobility for many groups, including the senior population (those over age 65) but also for non-drivers and people with medical conditions. This paper estimates bounds on the potential increases in travel in a fully automated vehicle environment due to an increase in mobility from the non-driving and senior populations and people with travel-restrictive medical conditions. In addition, these bounding estimates indicate which of these demographics could have the greatest increases in annual vehicle miles traveled (VMT) and highlight those age groups and genders within these populations that could contribute the most to the VMT increases. The data source is the 2009 National Household Transportation Survey (NHTS), which provides information on travel characteristics of the U.S. population. The changes to light-duty VMT are estimated by creating and examining three possible travel demand wedges. In demand wedge one, non-drivers are assumed to travel as much as the drivers within each age group and gender. Demand wedge two assumes that the driving elderly (those over age 65) without medical conditions will travel as much as a younger population within each gender. Demand wedge three makes the assumption that working age adult drivers (19–64) with medical conditions will travel as much as working age adults without medical conditions within each gender, while the driving elderly with medical any travel-restrictive conditions will travel as much as a younger demographic within each gender in a fully automated vehicle environment. The combination of the results from all three demand wedges represents an upper bound of 295 billion miles or a 14% increase in annual light-duty VMT for the US population 19 and older. Since traveling has other costs besides driving effort, these estimates serve to bound the potential increase from these populations to inform the scope of the challenges, rather than forecast specific VMT scenarios.     

Trip chain complexity: a comparison among latent classes of daily mobility patterns

This paper studies the relationship between trip chain complexity and daily travel behaviour of travellers. While trip chain complexity is conventionally investigated between travel modes, our scope is the more aggregated level of a person’s activity-travel pattern. Using data from the Netherlands Mobility Panel, a latent class cluster analysis was performed to group people with similar mode choice behaviour in distinct mobility pattern classes. All trip chains were assigned to both a travel mode and the mobility pattern class of the traveller. Subsequently, differences in trip chain complexity distributions were analysed between travel modes and between mobility pattern classes. Results indicate considerable differences between travel modes, particularly between multimodal and unimodal trip chains, but also between the unimodal travel modes car, bicycle, walking and public transport trip chains. No substantial differences in trip chain complexity were found between mobility pattern classes. Independently of the included travel modes, the distributions of trip chain complexity degrees were similar across mobility pattern classes. This means that personal circumstances such as the number of working hours or household members are not systematically translated into specific mobility patterns.

     

Fast-charging station choice behavior among battery electric vehicle users

This study explores how battery electric vehicle users choose where to fast-charge their vehicles from a set of charging stations, as well as the distance by which they are generally willing to detour for fast-charging. The focus is on fast-charging events during trips that include just one fast-charge between origin and destination in Kanagawa Prefecture, Japan. Mixed logit models with and without a threshold effect for detour distance are applied to panel data extracted from a two-year field trial on battery electric vehicle usage in Japan. Findings from the mixed logit model with threshold show that private users are generally willing to detour up to about 1750 m on working days and 750 m on non-working days, while the distance is 500 m for commercial users on both working and non-working days. Users in general prefer to charge at stations requiring a shorter detour and use chargers located at gas stations, and are significantly affected by the remaining charge. Commercial users prefer to charge at stations encountered earlier along their paths, while only private users traveling on working days show such preference and they turn to prefer the stations encountered later when choosing a station in peak hours. Only private users traveling on working days show a strong preference for free charging. Commercial users tend to pay for charging at a station within 500 m detour distance. The fast charging station choice behavior is heterogeneous among users. These findings provide a basis for early planning of a public fast charging infrastructure.     

An analysis of time allocation to in-home and out-of-home discretionary activities across working days and non- working days

The behavior of time allocation to two types of discretionary activities is formulated as a doubly-censored Tobit model. The model is capable of incorporating cases where the entire amount of time available for discretionary activity is allocated to one type of activity and the other type of activity is not engaged at all. The model is applied to examine individuals' allocation of time to in-home and out-of-home discretionary activities on working days and non-working days, using a weekly time-use data set from the Netherlands. Workers' daily activity patterns vary significantly between working days and non-working days, while it can be expected that patterns of time allocation are correlated between working days and non-working days. A set of error components is introduced into the model to represent this correlation, adopting a mass point approach which requires no assumption about the distribution of the error components. The validity of the model is examined statistically.     

An assessment of the benefits of the walking school bus in Christchurch,New Zealand

A Walking School Bus involves parents or other adults escorting a group of children on a set route to school. The first one was established in 1996 in Canada. They can now be found in a variety of countries, including New Zealand. Many of the benefits associated with them are based on the general benefits of affecting a modal shift away from cars in favour of walking. However, there is still relatively little known about the less quantifiable benefits of them, and there has been some suggestion that they can adversely affect children’s independent mobility. This research examined the perceived benefits of Walking School Buses by interviewing people involved in the day to running of the scheme in Christchurch, New Zealand. The results suggest that walking school buses have many social benefits and that if anything; they encourage children’s independent mobility.     

Walking to the bus: perceived versus actual walking distance to bus stops for older adults

The walking trip from an origin or destination to a bus stop or transit station can be a barrier to riding transit for older adults (over age 60) who may walk more slowly than others or experience declining physical mobility. This article examines the relationship between transit ridership and proximity to fixed-route transit stations using survey data for older adults in Buffalo and Erie County, New York. Demographic and socio-economic characteristics—including age, sex, race, income, possessing a driver’s license, frequency of leaving home, and personal mobility limitations—are tested but do not display, in bi-variate analysis, statistically significant differences for transit riders versus non-transit riders. However, features of the built environment—including distance (actual and perceived) between home and transit stop, transit service level, population density, number of street intersections, metropolitan location, and neighborhood crime (property and violent) rate—display statistically significant differences for transit riders versus non-transit riders. Both objective and perceived walking distances to access fixed-route transit show statistically significant differences between transit riders and non-transit riders. Average walking distance from home to transit for non-transit riders—who mostly live in suburbs—is three times greater than average walking distance between home and the nearest transit stop for transit riders—who mostly live in the central city. When asked how near a bus stop is to their homes, transit riders slightly overestimate the actual distance, while non-transit riders underestimate the distance.     

Substantial Changes and Their Impact on Mobility: A Typology and an Overview of the Literature

During the past 40 years, mobility patterns have enduringly changed several times as a result of the occurrence of a number “substantial changes”. Examples of such substantial changes are the rapid emergence of affordable air travel, the oil crises, and profound ICT developments. To most researchers and policy-makers in transportation, it seems more than likely that the next 40 years will also witness a number of substantial changes, some of which might even have larger impacts on mobility than the ones described above. However, literature on substantial changes and their impact on mobility are difficult to access as it is spread across different research fields and suffers from ambiguous use of terminology. As a result, overview of the literature on substantial changes and their findings is missing and discussions on the impacts on future mobility of potential substantial changes are hampered. To overcome these problems, this paper (1) proposes a typology of substantial changes and (2) ties together and reviews the scholarly literature that has focused on identifying the impacts of past substantial changes on mobility patterns. In this paper, we show how the proposed typology on substantial changes can be applied to contemplate on substantial changes and on their impacts.     

A panel data switching regression model of mobility and car ownership

The objective of this paper is to present a panel data model of car ownership and mobility. Unobserved heterogeneity is controlled for by including correlated random effects in the equations describing car ownership and mobility. A mass-points approach is adopted to control for unobserved heterogeneity. The results show that decisions concerning the first car in the household are difficult to affect; a large number of households are inclined to keep one car. Second car ownership may be more sensitive to changes in the observed contributing factors. This suggests that in The Netherlands policies aimed at changing second car ownership will be more successful than those aimed at influencing decisions concerning the first car in households. A major part of the correlation between the unobservables in the car ownership and the mobility equations is attributable to random effects. The time-variant errors of the mobility equations are not significantly correlated to car ownership decisions. This implies that mobility can only be influenced to a small extent by policy makers without measures aimed at reducing (second) car ownership.     

What is the relationship between online activity and driving-licence-holding amongst young adults?

There is growing interest amongst both practitioners and researchers in the correlates of young adults’ driving-licence-acquisition. One aspect of the ongoing scholarly debate is whether taking part in online (i.e. virtual) activities may be associated with young adults feeling less need to drive and hence to acquire a driving licence. This paper addresses this issue by drawing on analysis of two distinct datasets. Both contain rich pseudo-diary instruments in which people indicate detailed characteristics of their unique online-activity profile. This includes both indicators of the types of online activities in which respondents participate, and a separate metric of internet-use intensity. The latter is defined in one dataset as the amount of time/week spent online, and in the other dataset the frequency of their internet use. On the basis of a set of multivariate regression analyses, a positive (i.e. complementary) cross-sectional relationship between young adults’ online activity and licence-holding was found. We find that young adults who use the internet are, net of confounding effects, more likely to hold a driving licence than otherwise identical young adults who do not use the internet. Both datasets show this type of effect, and it is robust across a range of model specifications, including multi-stage estimations to address cross-correlation between indicators of internet usage. In addition to the positive net statistical association, we also report several other noteworthy effects. Of the six effects associated with online-activity types that are directly comparable between the two datasets, we find that the correlation in the parameter estimates across the two datasets is 0.63. This suggests similar types of relationships across the two datasets. Also, in several (but not all) of our analyses we found an inverted ‘U’ shaped ceteris paribus relationship between intensity-of-internet-use and licence-holding. The positive net statistical association between internet use and licence-holding is a different relationship than previously reported in the literature, and therefore further research is needed to reconcile the differences (which are likely due at least in part to different methodological approaches and data resources). Further research is also needed to continue to resolve between the relative saliency of other hypothesised determinants of licence-holding (e.g. economic and socio-demographic explanators, as well as licence-acquisition regimes that vary by time and place).     

Measurement biases in panel data

The objective of this paper is to examine reporting errors in panel data obtained from multi-day travel diaries. A distinction is made between within and between wave biases. The former leads to an increase in under-reporting associated with the number of days the diary is kept. The latter is related to the number of waves respondents have been participating, so-called panel experience. These biases imply that observed mobility changes between waves are partly due to reporting errors: without controlling for them, changes in mobility can not be inferred from the data. An important cause of these measurement errors is the increase in the number of days on which no trips at all were reported. In addition, shorter trips and less complex chains are more susceptible to underreporting. The methodology used in this paper provides a means of dealing with these problems. Attrition is taken into account by a rather simple measure. The paper concludes with a number of suggestions for sample and survey design.     

The same mode again? An exploration of mode choice variability in Great Britain using the National Travel Survey

The main focus of travel behaviour research has been explaining differences in behaviour between individuals (interpersonal variability) with less emphasis given to the variability of behaviour within individuals (intrapersonal variability). The subject of this paper is the variability of transport modes used by individuals in their weekly travel. Our review shows that previous studies have not allowed the full use of different modes in weekly travel to be taken into account, have used categorical variables as simple indicators of modal variability and have only considered a limited set of explanatory indicators in seeking to explain modal variability. In our analysis we use National Travel Survey data for Great Britain. We analyse modal variability with continuous measures of modal variability (Herfindahl–Hirschman Index, the difference in mode share between the primary and secondary mode, the total number of modes used). Taking inspiration from Hägerstrand (1970), we conceive that modal variability is determined by different types of spatial mobility constraints and find that reduced modal variability is predicted for having mobility difficulties, being aged over 60, being non-white, working full-time, living in smaller settlement, lower household income, having regular access to a car, having no public transport pass/season ticket and not owning a bicycle. The findings can support a change in perspective in transport policy from encouraging people to replace the use of one mode with another to encouraging people to make a change to their relative use of different transport modes.     

Carpooling and carpool clubs: Clarifying concepts and assessing value enhancement possibilities through a Stated Preference web survey in Lisbon, Portugal

The increase of urban traffic congestion calls for studying alternative measures for mobility management, and one of these measures is carpooling. In theory, these systems could lead to great reductions in the use of private vehicles; however, in practice they have obtained limited success for two main reasons: the psychological barriers associated with riding with strangers and poor schedule flexibility. To overcome some of the limitations of the traditional schemes, we proposed studying a carpooling club model with two main new features: establishing a base trust level for carpoolers to find compatible matches for traditional groups and at the same time allowing to search for a ride in an alternative group when the pool member has a trip schedule different from the usual one. A web-based survey was developed for the Lisbon Metropolitan Region (Portugal), including a Stated Preference experiment, to test the concept and confirm previous knowledge on these systems’ determinants. It was found through a binary logit Discrete Choice Model calibration that carpooling is still attached with lower income strata and that saving money is still an important reason for participating in it. The club itself does not show promise introducing more flexibility in these systems; however, it should provide a way for persons to interact and trust each other at least to the level of working colleagues.     

An analysis of destination choice for opaque airline products using multidimensional binary logit models

We investigate how customers respond to an opaque airline product offered by a European carrier. In this opaque product design, customers are randomly assigned to travel to one of approximately ten destinations; however, for a fee they may exclude one or more destinations from the choice set (or a particular package design) prior to learning which destination they will travel to. We use a multidimensional binary logit model to predict the probability that one or more alternatives will be chosen by a customer. Results show that customers are more likely to pay to exclude destinations located close to the origin airport and destinations that speak the same language as the origin airport. Length of stay, cost of living at the destination, and measures of destination attractiveness are also found to be significant predictors for some package designs. Based on these findings, we offer general recommendations for how to design opaque packages for airline customers.     

Multi-criteria optimization of traffic signals: Mobility,safety, and environment

Two-dimensional multi-objective optimizations have been used for decades for the problems in traffic engineering although only few times so far in the optimization of signal timings. While the other engineering and science disciplines have utilized visualization of 3-dimensional Pareto fronts in the optimization studies, we have not seen many of those concepts applied to traffic signal optimization problems. To bridge the gap in the existing knowledge this study presents a methodology where 3-dimensional Pareto Fronts of signal timings, which are expressed through mobility, (surrogate) safety, and environmental factors, are optimized by use of an evolutionary algorithm. The study uses a segment of 5 signalized intersections in West Valley City, Utah, to test signal timings which provide a balance between mobility, safety and environment. In addition, a set of previous developed signal timing scenarios, including some of the Connected Vehicle technologies such as GLOSA, were conducted to evaluate the quality of the 3-dimensional Pareto front solutions. The results show success of 3-dimensinal Pareto fronts moving towards optimality. The resulting signal timing plans do not show large differences between themselves but all improve on the signal timings from the field, significantly. The commonly used optimization of standard single-objective functions shows robust solutions. The new set of Connected Vehicle technologies also shows promising benefits, especially in the area of reducing inter-vehicular friction. The resulting timing plans from two optimization sets (constrained and unconstrained) show that environmental and safe signal timings coincide but somewhat contradict mobility. Further research is needed to apply similar concepts on a variety of networks and traffic conditions before generalizing findings.     

Mitigating air pollution impacts of passenger ferries

Increasing regional mobility demand amid rising roadway congestion has motivated plans for passenger ferry expansion and modernization in many parts of the US. While this trend applies to ferry systems in Alaska, New York, Boston, and Washington state, efforts to expand ferry service in the San Francisco Bay Area are unique in scale and vision. Integrating ferry service into the regional, door-to-door transit system can significantly increase water-crossing capacity for commuters. However, to realize this potential, the ferry industry must meet several challenges associated with growth, including environmental impacts. In particular, concern over air pollution emissions from marine engines is motivating new comparisons between ferries and other transportation modes in terms of both mobility and air pollution. This paper describes the current debate about ferry system operation and expansion, and presents a parametric analysis comparing existing, uncontrolled ferry emissions to automobiles. Under all reasonable assumptions, we show that diesel-powered ferries without emissions controls will produce more NO_x and PM, but less CO per passenger-trip than if those people commuted by car under current conditions. This paper also projects the emissions from the expanded ferry system proposed for the San Francisco Bay Area, showing that a larger ferry fleet equipped with new engines meeting future EPA emissions standards could become one of the major non-road NO_x sources in the region. We conclude by outlining the alternatives and challenges to reduce ferry emissions so that they are more comparable to automobile emissions. Policy implications of these alternatives are also discussed.     

Weekly mobility of life cycle groups

This paper describes parts of a study of travel by urban residents on seven consecutive days. The conceptual structure of the research understands travel as a demand derived by a dynamic process of individuals and households allocating their budgets to activities within the framework posed by societal regimens. Societal rules have a time dimension which is repetitive with a weekly cycle. Thus, distinctive basic patterns of weekly mobility are expected for segments of the society and differences in the obligation to adhere to those basic patterns. The data used for testing these hypotheses is described and the issue of increasing reporting bias over the diary period is addressed. Sixteen life cycle groups of persons are selected here for the presentation of some findings.The profiles of trip rates for the groups over the seven days of the week (estimated with analysis of covariance) and the decomposition of the variances of trip rates into interindividual, intraindividual and systematic parts (by repeated measurement analysis) are reported. Characteristic differences in the volume of mobility, the shape of profiles and the variance components reflect different patterns of tripmaking for segments of the population over the week. It is concluded that even for well-defined person categories, interpersonal variety of mobility behavior is large but has to be seen in relation to even greater intrapersonal variability. Both components can best be understood within the period of one week which individuals use to organize their mobility.     

Impacts of a multimodal mobility service on travel behavior and preferences: user insights from Munich’s first Mobility Station

The City of Munich, in cooperation with the local public transport provider MVG, is testing a pilot project of a “Mobility Station”, which is a multimodal mobility hub connecting public transport (PT) and new shared mobility services. The project’s goal is to provide sustainable mobility options that allow citizens to be mobile without owning a car. To evaluate the acceptance of the Mobility Station, as well as short and long term effects on mobility behavior, we developed an online user survey in close cooperation with the stakeholders and experts in the field of shared mobility. The results provide insights on the awareness and perception of the Mobility Station among users, their mobility patterns, current degree of multimodality, as well as actual and potential changes on mobility behavior and travel preferences due to the multimodal mobility service. Most users are young, male, and highly educated individuals with access to multiple mobility options. PT plays a central role for daily mobility together with the services they were identified to be customers of. The high share of users that use different mobility services at least once a month indicates some degree of multimodality. Actual and potential changes in mobility behavior towards multimodality were revealed. Some users declared to use other mobility services more often. They appreciate the availability of different mobility options and show interest in other services and intermodal connections indicating that there is still potential to increase multimodal behavior.