Superbus: Using Aerospace Technology to Make High Speed Public Transport More Sustainable
J A Melkert, Delft University of Technology, NL
The Superbus concept consists of a high speed road vehicle, high speed infrastructure and an advanced logistic support system. The maximum speed is 250 km/h. In the development aerospace technology has been used to reduce environmental impact.
The Superbus concept is being developed by TU Delft in the Netherlands. It consists of a high speed road driven vehicle for use in public transport, dedicated high speed infrastructure and advanced logistic support systems for its demand driven operation. The concept has been evaluated in the framework of the Dutch high speed connection between the West and the North of the country, the so-called Zuiderzeelijn. In this evaluation procedure the Superbus was compared with other modes of high speed public transport. The paper describes the Superbus concept, the assessment procedure used by the Dutch government to assess all possible modes of public transport on the Zuiderzeelijn-connection and will conclude by reporting the results.
Development of the Superbus concept
The Superbus concept was invented by TU Delft in 2004. The basic idea was to develop a road driven high speed vehicle, using aerospace and other advanced high-tech in order to reduce the environmental impact of high speed public transport. The design maximum speed of the Superbus is 250 km/h while the power required at that speed will be comparable with that of existing buses driving 100 km/h. This can be done by addressing the two main sources of drag: aerodynamic drag and rolling resistance. Aerodynamic drag is determined by both the shape and the size, mainly frontal area. By streamlining the vehicle and reducing its height the aerodynamic drag can be reduced significantly. The rolling resistance is mainly determined by the weight of the vehicle. By using fiber reinforced composites and aerospace construction methods the weight of the vehicle and thus the rolling resistance can be reduced.
In the development an aerospace safety approach is used. The national road safety authority is involved in the project from the start.
The choice for a road driven vehicle is made because of freedom it gives in choosing its path. While rail bound public transport is limited to its rail infrastructure a road driven vehicle is not. The Superbus will be able to make use of existing infrastructure where possible and make use of dedicated high speed infrastructure when needed. This dedicated high speed infrastructure will be purpose built. It can therefore be designed for the loads of the Superbus. One does not have to take into account the same design load criteria as used in design of standard roads because of usage by heavily loaded trucks. The Superbus therefore requires a relatively light road structure. This will reduce both costs and environmental impact.
Environmental impact of public transport
The environmental impact of a public transport system is mainly being determined by the construction of dedicated infrastructure and the operation of vehicles over a certain period. It has been shown that for public transport systems the environmental impact over its life cycle is determined for a considerable part by the construction of the dedicated infrastructure. The paper will look into these two main aspects.
Assessment of the Superbus concept
TU Delft was given the opportunity to have the Superbus concept assessed by the Dutch government in the framework of the Zuiderzeelijn-connection. The government studied five different modes of public transport which could be used on this connection. In this assessment the concept was assessed on aspects like societal costs and benefits and environmental impact. Next to that the possibilities to develop a profitable operation were assessed. For this the government invited a consortium of companies to develop a business case for the Superbus. The result of the assessment was that the government decided not to further develop the Zuiderzeelijn-connection itself.
However, since the assessment results showed the Superbus concept to be the most profitable of the transport modes investigated the government decided to start a research and development program. In the framework of that program TU Delft is now developing a full scale demonstration vehicle of the Superbus and in parallel researching the possible applications, both in the Netherlands and abroad.
The paper will conclude with presenting the results gained during the research. It will make a comparison between the Superbus and other modes of high speed transport, focusing on the environmental impact. Aspects addressed in the assessment of the environmental impact are the energy consumption, the effects on soil and water, noise and the effect of its dedicated infrastructure on the built and rural environment. It will be shown that the Superbus concept is superior or at least equal compared to the other modes of high speed public transport in all aforementioned aspects.
Association for European Transport