A multidisciplinary design team consisting of undergraduate and graduate students from Aerospace Engineering, Applied Earth Sciences, Industrial Design and Mechanical Engineering at the Delft University of Technology in the Netherlands is designing a lightweight, sustainable car. 1 Their goal is to design a family car with a maximum mass of 400 kg. Mass is an important factor in the fuel consumption of a car, a light car can be very energy efficient. The target mass is less than half of that of normal cars. (European family cars usually weigh about 1200 kg and the average American car weighs 1360...
A multidisciplinary design team consisting of undergraduate and graduate students from Aerospace Engineering, Applied Earth Sciences, Industrial Design and Mechanical Engineering at the Delft University of Technology in the Netherlands is designing a lightweight, sustainable car. 1 Their goal is to design a family car with a maximum mass of 400 kg. Mass is an important factor in the fuel consumption of a car, a light car can be very energy efficient. The target mass is less than half of that of normal cars. (European family cars usually weigh about 1200 kg and the average American car weighs 1360 kg). Another requirement is that the car should be manufactured at affordable mass production costs. 2
The design of such a unique car presents not only significant technical hurdles, but it also introduces many ethical issues such as minimum safety requirements and the need to incorporate sustainability considerations. This web-based case study will present the major safety and sustainability points in the ethical debate over ultra-lightweight vehicles and then ask the reader to consider a series of thought-provoking questions for both topics. For those using this website for an assignment, you have the option of sending your responses to your professor or teaching assistant.
In addition to reading and responding to the ethical issues in the design of ultra-lightweight vehicles, interested readers can see how the answers to both sets of questions from a sample of students from the United States compared to those of Dutch students. The case study was piloted in a Technology and Ethics class comprised of engineering students from various disciplines at the University of Virginia as well as a group of students in Aerospace Engineering at Delft University of Technology. While many answers were very similar between the two distinctly different student groups, many attitudes are quite different. Educators using this case may want to add an additional question to the assignment that asks students hypothesize why answers between the two groups of engineering students may be similar or different.
We would like to thank the DutchEVO design team for their cooperation. This research was sponsored by an NSF grant (#0135585) for the Online Ethics Center under the direction of Caroline Whitbeck.
Pictures courtesy of the DutchEVO.
The goal of reducing the mass to 400kg has generated a debate over safety concerns when building a lightweight car. A car that is relatively light always has a disadvantage in collisions with larger cars in that it will always experience the greater acceleration. Traditional automobile safety considerations have resulted in designs of very heavy and stiff vehicles, protecting the driver and passengers in a collision but at the same time constituting a hazard for other road users in lighter vehicles because of their significantly reduced stiffness and mass. In addition, heavier vehicles are not as fuel efficient.
Recent developments in automobile safety have led to the increasing use of passive safety systems 1 such as airbags and active systems like Anti-lock Braking System and night vision enhancements. Designing in the conventional way means that safety systems are included as much as economically feasible. In a car of 400 kg or less it is very difficult to include extensive active and passive safety systems, so the design of a lightweight car necessitates a reconsideration of the ideas of what constitutes adequate car safety. Is it a car that performs well in crash tests, or is it a car that helps the driver to brake suddenly to avoid a crash? 2
There is a theory within safety science that states that people have a target risk that guides their behavior, and this is called risk homeostasis. People will try to keep the perceived risk at the same level. A driver that feels safe and protected by her car will speed more. This could lead to accidents with higher speeds involved and therefore more injuries and damage. The same driver would probably not speed in a subcompact, as she will probably feel more vulnerable. Therefore, there might be good arguments to build a car with less active and passive safety systems. The Delft student designers have chosen to design a car with few systems, good handling, but one that makes the driver feel a bit vulnerable. This choice is inspired by the lightweight criterion and the risk homeostasis theory.
Questions and comments about this case can be directed to Missy Cummings, Massachusetts Institute of Technology or Anke van Gorp, Delft University of Technology.
Picture courtesy of Rocky Mountain Institute and HyperCar Center®
Next: Safety Questions (Ethical Issues in the Design of Ultra-Lightweight Vehicles)