The use of private cars has grown rapidly during the last decades. Car usage is growing because the car is an attractive mode of transportation. In comparison with other travel modes, the car is comfortable, fast, reliable, flexible and convenient. But the growth of car use causes serious problems. Because of all the negative impacts of car usage, the current transportation system is not sustainable. The negative impact of car traffic needs to be managed. To achieve a long-term sustainable transport system, households need to reduce their use of private cars, especially in peak hours. The car should be the focus because this is the most used commuting transportation mode. All the proposed measures concerning the change or the reduction of the demand for car use, are part of Travel Demand Management (TDM). One of the newest trends in TDM is carsharing, a short-term car rental service in which service members can rent a car and pay per hour or mile of use. Companies could introduce or implement such carsharing opportunities in their mobility plans to discourage car commuting under their employees, this is called a Supportive Car System (SCS). An SCS is a car system, available at the working location and shared by employees to support in particular goals as business trips and other work-related purposes.
The objectives of this research are finally to contribute to the improvement of this specific TDM measure. In the first place, this was done by identifying the most important attributes of an SCS, supported by companies/organizations, to optimize the potential and acceptance of the system. With these attributes, the optimal setting for the adoption of the SCS could be reached. Secondly, it needs to be identified if the optimal system could influence the commuting mode choice of the employees to discourage the car as commuting traffic.
A literature review to SCS attributes resulted in the user attributes in this research. The most important attributes of an SCS are the location of the SCS (walking time to the car), the amount of advertisements on the car, the type of car, the tariff systems of the car (per reserved time and per driven kilometer), the type of fuel, the accessibility of the car (how to unlock the car), the availability of the car (in which time slots the car is available), reservation techniques of the car and for which type of trip purpose the car could be used.
To research the importance of the SCS attributes and if they are influencing the respondents’ choice when selecting an SCS a stated choice (SC) method will be used. This approach allows this study to estimate the respondents’ preferences and predict the respondents’ choice probabilities for the alternatives. And it has the ability to use choice situations that do not yet exist.
Besides the respondents’ preferences, a goal of the research is to check if an SCS influences the commuting mode choice of people. The transportation mode choice depends on different factors. It all starts with the sociodemographic aspects of a person. These are on influence on the transportation mode choice decision process. In this process, people have travel needs. There is a hierarchy in those needs. In order of importance: the feasibility and accessibility of a certain transportation mode, the basic safety and security, the convenience and costs of a certain transportation mode, enjoyment and pleasure and in the end also habit is a factor in the transportation mode choice decision process.
A web-based survey has been used for this research. The survey was spread amongst 8.800 employees and students as a case study at the Eindhoven University of Technology (TU/e). The main part of this survey is the SP experiment, where respondents needed to select one of the two offered Supportive Car Systems. According to the (with fractional factorial designed) choice tasks with above-mentioned attributes, the respondents needed to select their favorable SCS. The car commuters also needed to answer the question if they are likely to change their car commuting mode if the selected SCS is available at their working location. After data preparation, the survey resulted in 383 respondents for further research. The importance and influence of the SCS attributes are analyzed with a multinomial logit (MNL) model. The willingness of the car commuters to change commuting mode is analyzed with a binary logit choice model.
The results of this research state that the availability of the SCS is a very important attribute when selecting an SCS for all the (sub)groups. Other very important attributes are the tariff systems and the type of fuel. Less important attributes are the location of the SCS, the presence of advertisements on the SCS and the reservation possibilities. The least important attributes for the SCS are the type of car, the accessibility of the SCS and the trip purposes. The optimal setting of an SCS, according to this research is an electric SCS that costs €0.30 per kilometer or €4 per hour. A system that is available for 24 hours a day, 7 days per week, to use for every possible trip purpose. The SCS is located at a walking duration of 1 minute from the user’s location. There is a mobile application available to reserve and unlock the car. The optimal design of the SCS is a luxurious car with only the logo of the company on the exterior. The biggest part of the people who commute by car is not willing to change their commuting mode (41%) if the preferred SCS is available. 24% is willing to change their commuting mode the train, 21% to the bicycle and 14% to the bus. The most important settings to achieve this goal are a price of €0.30 per km or €4 per hour, the availability of the SCS of 24 hours per day, 7 days per week and it has to be an electric vehicle.