Rates of car ownership in the United States exceed that of all other large nations in the world. This high rate contributes to the unexpressed demand for road space that renders highway expansion useless as a strategy for decreasing traffic congestion. It also necessitates the provision of on-site parking in residential buildings, decreasing the affordability of housing in urban areas. Furthermore, the curb-side parking needed to make room for the high number of cars in the country takes away space that could be used for bike lanes, transit lanes, or widened sidewalks. Therefore, the United States could benefit from a reduction in rates of household car ownership. In this paper, I use cross-sectional data from the National Highway Transportation Survey to determine the impact on heavy and light rail on car ownership in American cities. I find that the presence of heavy rail is associated with a lower rate of car ownership, while the presence of light rail is not.

Transportation sector has been a major contributing factor to the overall emissions of most pollutants and thus their impacts on the environment. Among all transportation activities, on-road travel accounts for most part of the Greenhouse gas (GHG) emissions and fuel use. It also has a very un-desirable impact on the transportation network conditions increasing the traffic congestion levels. The main aim of transportation planning agencies is to implement the policy changes that will reduce automobile dependency and increase transit and non-motorized modes usage. However, planning agencies can come up with proactive economic, land-use and transportation policies provided they have a model which is sensitive to all the above mentioned factors to predict the vehicle fleet composition and usage of households. Moreover, the type of vehicle that a household gets (vehicle type choice) and the annual mileage (usage) associated with that vehicle is very closely related to the person in the household who uses that vehicle the most (allocation to primary driver). So, it is no longer possible to view all these decisions separately. Instead, we need to model all these decisions- vehicle type choice, usage, and allocation to primary driver simultaneously at a household level. In this study, we estimate and apply a joint household-level model of the number of vehicles owned by the household, the vehicle type choice of each vehicle, the annual mileage on each vehicle, as well as the individual assigned as the primary driver for each vehicle. A version of the proposed model system currently serves as the engine for a household vehicle composition and evolution simulator, which itself has been embedded within the larger SimAGENT (for Simulator of Activities, Greenhouse emissions, Networks, and Travel) activity-based travel and emissions forecasting system for the Southern California Association of Governments (SCAG) planning region. / text

This licentiate thesis, with the English title Automobility towards Regional Equality? Studies of the geographical and socioeconomic diffusion of the private automobility in Sweden 1950-2000, has the overall aim to investigate the interaction between the private automobility and the Swedish socio-economical development in general. Firstly, the diffusion of private car ownership in Sweden is mapped both geographically and economically at the national level covering all citizens above the age of 18. Secondly, a comparison with the Norwegian diffusion pattern shows how automobility has interacted with two partly different national contexts. This aim will be dealt with in two articles. Since the diffusion of private cars in Sweden has not yet been examined in a long run and national perspective covering all individuals, the first article, Driving from the Centre to the Periphery? The Diffusion of Private Cars in Sweden 1950-2000 with focus on 1960-1975, investigates how the diffusion of private cars followed the over all socio-economic and geographical changes from 1960 to 1975; did changes in car ownership per capita primarily follow changes in incomes or changes in population density (urbanisation)? Swedish traffic and regional policies in the 1960s aimed at making the car an instrument for national integration and regional equality, and make it available throughout the country. In the article the effect of that policy is tested. The analysis is based on Swedish census material that includes all car owners for the years 1960, 1970 and 1975. Our conclusion is that income levels were more important than other explanations to the diffusion of private cars in Sweden between 1960 and 1975. Since Norwegian private car density has lagged behind the Swedish and did not reach the same national levels until the late 1980s, despite the same GDP per capita levels, the second article, Two Sides of the same Coin? Private Car Ownership in Sweden and Norway since 1950, compares car diffusion in Norway and Sweden in both historical time and model time in order to find specific explanations for the national and regional patterns of car diffusion. Can both the time lag and the diffusion process be explained with national differences in income, institutions, infrastructure, and population settlements? Or have regional differences in income and population density affected the outcome? Our conclusion is that car diffusion in Norway and Sweden displays two sides of same coin; the national levels converged, but the process did not follow the same regional pattern. Regional differences in income and population density have in general been a significant explanation for car density in Sweden but not in Norway. Thus, the licentiate thesis shows how private car ownership in Sweden from the 1950s has interacted with increasing regional equality, especially concerning geographical diffusion. / På omslaget år 2007.

The elderly and persons residing in zero vehicle households require better transportation services by virtue of their need for special care and lack of mobility, respectively. An analysis of the travel trends of these population cohorts is essential to determine the best ways to improve transportation facilities to better serve them. Information about location of residence, life-cycle, differences by gender, employment status, driver status, highest level of education coupled with trip information like trip rate, travel times and distances trip purpose, modal split and percent of people immobile will facilitate understanding the factors that influence trip making among these people and help predict travel trends for the future. This work attempts to analyze the elderly and persons residing in zero vehicle households in the United States by using NHTS 2001 and NPTS 1990 datasets for the purpose of analysis and comparison.

<p>This licentiate thesis, with the English title Automobility towards Regional Equality? Studies of the geographical and socioeconomic diffusion of the private automobility in Sweden 1950-2000, has the overall aim to investigate the interaction between the private automobility and the Swedish socio-economical development in general. Firstly, the diffusion of private car ownership in Sweden is mapped both geographically and economically at the national level covering all citizens above the age of 18. Secondly, a comparison with the Norwegian diffusion pattern shows how automobility has interacted with two partly different national contexts. This aim will be dealt with in two articles.</p><p>Since the diffusion of private cars in Sweden has not yet been examined in a long run and national perspective covering all individuals, the first article, Driving from the Centre to the Periphery? The Diffusion of Private Cars in Sweden 1950-2000 with focus on 1960-1975, investigates how the diffusion of private cars followed the over all socio-economic and geographical changes from 1960 to 1975; did changes in car ownership per capita primarily follow changes in incomes or changes in population density (urbanisation)? Swedish traffic and regional policies in the 1960s aimed at making the car an instrument for national integration and regional equality, and make it available throughout the country. In the article the effect of that policy is tested. The analysis is based on Swedish census material that includes all car owners for the years 1960, 1970 and 1975. Our conclusion is that income levels were more important than other explanations to the diffusion of private cars in Sweden between 1960 and 1975.</p><p>Since Norwegian private car density has lagged behind the Swedish and did not reach the same national levels until the late 1980s, despite the same GDP per capita levels, the second article, Two Sides of the same Coin? Private Car Ownership in Sweden and Norway since 1950, compares car diffusion in Norway and Sweden in both historical time and model time in order to find specific explanations for the national and regional patterns of car diffusion. Can both the time lag and the diffusion process be explained with national differences in income, institutions, infrastructure, and population settlements? Or have regional differences in income and population density affected the outcome? Our conclusion is that car diffusion in Norway and Sweden displays two sides of same coin; the national levels converged, but the process did not follow the same regional pattern. Regional differences in income and population density have in general been a significant explanation for car density in Sweden but not in Norway.</p><p>Thus, the licentiate thesis shows how private car ownership in Sweden from the 1950s has interacted with increasing regional equality, especially concerning geographical diffusion.</p>

This thesis consists of two parts. The first part analyzesthe accessibility, generation and license holding effects incar ownership models. The second part develops a route choicemodeling framework with an attempt to address the differencesin drivers' route choice behavior. These two parts of work areboth based on the discrete choice theory - the car ownershipmodels are built up on the standard logit model, whereas theroute choice models are formulated in a mixed logit form. The study result of the first part shows that measuring theaccessibility by the monetary inclusive value reasonably wellcaptures the mechanism of the accessibility impact. Otheraccessibility proxies such as the parking costs, parking typeand house type are correlated with the accessibility but not toa great extent. Both young and old households are less likelyto have a car. The reduction of the propensity to own a car issignificant for households with average birth year before 1920,whereas this reduction is moderate for households with birthyear between 1920 and 1945. It is also demonstrated thatdriving license holding choice is conditional on the carownership level choice, and that these two choices need to bemodeled in a dynamic framework. The second part of the work investigates the performance ofthe mixed logit model using both simulated data and empiricalroute switching data. The empirical study mainly focused on theimpacts of information and incident related factors on drivers'route switching behavior. The result shows that using mixed logit gives a significantimprovement in model performance as well as a more sensitiveexplanation of drivers' decision-making behavior. For apopulation with greatly varying tastes, simply using thestandard logit model to analyze its behavior can yield veryunrealistic results. However, care must be taken when settingthe number of random draws for simulating the choiceprobability of the mixed logit model in order to get reliableestimates. The empirical results demonstrate that incident relatedfactors such as delay and information reliability havesignificant impacts on drivers' route switching, where themagnitude of the response to the change in the delay is shownto vary significantly between individuals. Other factors, suchas confidence in the estimated delay, gender, frequency of cardriving and attitude towards congestion, also make majorcontributions. In addition, it is found that individual's routeswitching behavior may differ depending on the purpose of thetrip and when the choice is made, i.e. pre-trip oren-route. <b>Keywords</b>: car ownership, accessibility, logit model,route choice, heterogeneity, mixed logit model

<p>This thesis consists of two parts. The first part analyzesthe accessibility, generation and license holding effects incar ownership models. The second part develops a route choicemodeling framework with an attempt to address the differencesin drivers' route choice behavior. These two parts of work areboth based on the discrete choice theory - the car ownershipmodels are built up on the standard logit model, whereas theroute choice models are formulated in a mixed logit form.</p><p>The study result of the first part shows that measuring theaccessibility by the monetary inclusive value reasonably wellcaptures the mechanism of the accessibility impact. Otheraccessibility proxies such as the parking costs, parking typeand house type are correlated with the accessibility but not toa great extent. Both young and old households are less likelyto have a car. The reduction of the propensity to own a car issignificant for households with average birth year before 1920,whereas this reduction is moderate for households with birthyear between 1920 and 1945. It is also demonstrated thatdriving license holding choice is conditional on the carownership level choice, and that these two choices need to bemodeled in a dynamic framework.</p><p>The second part of the work investigates the performance ofthe mixed logit model using both simulated data and empiricalroute switching data. The empirical study mainly focused on theimpacts of information and incident related factors on drivers'route switching behavior.</p><p>The result shows that using mixed logit gives a significantimprovement in model performance as well as a more sensitiveexplanation of drivers' decision-making behavior. For apopulation with greatly varying tastes, simply using thestandard logit model to analyze its behavior can yield veryunrealistic results. However, care must be taken when settingthe number of random draws for simulating the choiceprobability of the mixed logit model in order to get reliableestimates.</p><p>The empirical results demonstrate that incident relatedfactors such as delay and information reliability havesignificant impacts on drivers' route switching, where themagnitude of the response to the change in the delay is shownto vary significantly between individuals. Other factors, suchas confidence in the estimated delay, gender, frequency of cardriving and attitude towards congestion, also make majorcontributions. In addition, it is found that individual's routeswitching behavior may differ depending on the purpose of thetrip and when the choice is made, i.e. pre-trip oren-route.</p><p><b>Keywords</b>: car ownership, accessibility, logit model,route choice, heterogeneity, mixed logit model</p>

This thesis analyzes the car ownership and use issues worldwide and in Ankara. There has been an extremely rapid increase in car traffic in major cities, leading to car dependence and its adverse affects, all over the world. This thesis takes its starting point the driving forces behind car ownership and use, and the increasing problems caused by the car traffic in urban centers. Then, car travel reduction measures and their consequences are reviewed by examples. The urban transportation in Ankara is analyzed, both in terms of recent policies and the data obtained, in order to find out if the car ownership and use would generate similar problems in Ankara. The applicability of car travel reduction options in Ankara and the conflicts in the recent urban transportation policies are discussed. This research does not recommend simple solutions, but concludes that a broad spectrum of measures must be applied in order to reduce the problems.

The purpose of this study was to investigate how the use of the private car has developed throughout history and to describe options for private use of private cars. The study aimed to investigate how municipalities in Sweden encourage and support their residents away from private car ownership to reduce car traffic. The study is based on literature research and a survey which were sent to 30 municipalities in Sweden to study the work of shared use of vehicle, shared mobility, combined mobility and mobility management interventions which aims to, by changing travellers’ attitudes and behaviour reduce private car use. Private cars are a major source to anthropogenic emissions of carbon dioxide which contributes to climate change and global warming. Renewable fuels and fuel efficient vehicles are part of the solutions for reducing the emission of carbon dioxide, but also reduce private car use. The result of the survey showed that mobility management interventions were most common. More than half of the municipalities offered shared mobility, especially the larger municipalities. Combined mobility was not offered by the municipalities today. Municipalities state that they are both working on a strategy to reduce private car use along with various other projects. Challenges with the strategies to reduce private car use were reported to be the work of getting different actors to move in the same direction, toward reduced emissions from private car use.

Abstract A great deal of research in transportation economics has been motivated by the need to solve traffic congestion problems and to diminish negative environmental effects of road transport. The question, whether the economic measures are efficient, motivates this dissertation on the value of travel time, the rules of optimal pricing and the demands for public transportation and private car use. Three concepts of the marginal value of travel time (MVT) are specified in this thesis. The first concept involves only the direct disutility of the travel time to work in addition to the utility of market goods and leisure. The second concept also includes the disutility from the time spent at work. The third concept furthermore takes into account the effect of the length of working hours, travel time, cost and income. The length of travel time, gender, family structure and flexibility of working hours have different effects on empirical MVTs, but travel costs and income affect them in a similar fashion. The pricing decisions of the firms providing bus services are analysed with and without public subsidies. The consumption externality, i.e. the quantity demanded by other users, affects the individual bus demand. The results indicate that under uniform pricing, a socially optimal subsidy equals the increase in consumer's surplus minus the fare revenue lost from current users due to lower fare. Under nonlinear pricing, the optimal pricing can be achieved when the regulator sets the subsidy so that it is inversely proportional to the network elasticity. The welfare loss due to increasing tax burden and the opportunity cost of providing cash fare service is also taken into account in the optimal pricing rule. A model of bus demand with asymmetric information on the characteristics of bus users is developed. The model allows for habit formation and network effects. The latter effect is due to the positive influence of the aggregate demand for Regional Bus Cards (RBC) on an individual's own demand. The empirical results indicate that in RBC services positive network effects are present and the elasticity of network size is less than one, which implies that the regional bus card is an impure public good. The own price elasticity of RBC in the short run is within the range of -0.3 and -1.1. The demand for RBC cards is more elastic than demand for RBC trips or passenger kilometres. The estimated price elasticity of urban bus demand is in line with that of RBC. A reasonably high cross-price elasticity of RBC trips and the ticket of 40 trips but a lower reverse elasticity were found. A weakly separable demand for car mileage from car ownership and labour supply was rejected as was the exogeneity of car ownership in the mileage model. Therefore, the price elasticity of car mileage with respect to fuel price was estimated from the two equation model of car mileage with endogenous car ownership. The estimated parameters of the Tobit model are consistent but slightly higher than those estimated from the least squares. The fuel price elasticity varies from -0.2 to -0.9 with exogenous and endogenous car ownership, respectively. The findings of this study can be applied in the analysis and implementation of different pricing and subsidy schemes for public transportation, as well as in the evaluation of the effectiveness of economic instruments for managing the growth of private car use.