Accident research at LMU
Curbing traffic deaths
Wolfram Hell studies how – and why – traffic accidents occur. His goal is to find ways of reducing the number of fatal crashes by optimizing the efficiency of vehicle safety systems. But his findings don’t always find a receptive ear.
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The driver nonchalantly steers his dump truck onto the main road. Seconds later the 16-tonner comes to an abrupt halt, but is now facing in the direction from which it has just come. The reason for the sudden turnabout is that the truck has just been hit by a small car travelling at 70 km/h, and the impact was enough to rotate the truck by 180°.
In the car were a young mother, at the wheel, and her two children, the elder in the passenger-seat and a 2-year-old strapped into a children’s seat in the back. The good news is that all survived the crash. – Despite the fact that the car sustained severe damage, its occupants escaped with “light to moderate” injuries. The bad news is that the younger child suffered a spinal injury and is paralyzed, although the rear compartment of the car shows little sign of damage. “The problem was that the children’s seat was 18 years old, and the straps were much too loose,” says pathologist and accident researcher Dr. Wolfram Hell who, among other things, acts as an advisor on child protection to the consumer watchdog Stiftung Warentest. In this case, the simple, bitter truth is that the youngest victim of the accident was not securely strapped in.
Hell is Head of the Section on Medical and Biomechanical Accident Research (MBU) at LMU’s Institute of Forensic Medicine, and he describes the circumstances surrounding this accident with sober, professional detachment. It was only one of the many that he deals with every day, but in one respect it was untypical: In most of the accidents he studies, there are no survivors.
Interdisciplinary accident research
In the “Ufo Lab.” (from the German term for accident research) on the second floor of the Institute for Forensic Medicine on Nussbaumstrasse, advanced undergraduates and doctoral candidates are at work on their research projects, under the direction of Professor Hans Bäumler. Bäumler is Professor of Automotive Engineering at Munich’s University of Applied Sciences, and collaborates closely with Wolfram Hell, who is responsible for the analysis of the medical and biomechanical aspects of accident research. The interdisciplinary nature of their cooperation allows them to consider both the vehicles and the human actors in the lead-up to a collision and its aftermath. One investigates the damage done to the vehicles involved and looks for any technical defects that might have contributed to the accident. The other focuses his attention on the victims, carrying out post-mortem examinations if necessary to determine the kind and the severity of the injuries inflicted on driver and passengers.
This explains why the various members of the research team are all engaged in very different kinds of projects. Doctoral student Klaus Bauer, for instance, simulates accidents involving cyclists, while Diplom student Florian Plöchinger studies accidents that occur during turning maneuvers at intersections. PhD student Michael Rasch is building up a database (which is called SUD, for Sicherheits-Unfall-Datenbank) on fatal traffic accidents and their victims. – About 150 autopsies are carried out on such unfortunates in the basement each year. “We have now compiled and incorporated complete sets of accident statistics for a period of several years,” Rasch says. All the factors relevant to the outcome go into SUD: the sequence of events that led to the accident, the weather conditions at the time, the technical state of the vehicles involved, the condition of the driver after the accident, and the nature of the fatal injuries. SUD documents the breakage of a carbon-ceramic brake-disk in an expensive sportscar – and the fact that it occurred after the driver had suffered a heart-attack while travelling at 200 km/h. It records the blockage in the brake hose, the blood-alcohol level of the speed merchant who was at the wheel, and the very high velocity of his skidding vehicle just before it was stopped by the wall of a house.
“When we have identified a technical fault in a particular model of vehicle as a contributory factor in accidents, we inform the Technical Inspectorates,” Hell explains. “For instance, if a brake hose is susceptible to blockage because the materials used in its manufacture are the cheapest available, that is not something that is likely to be noticed during a regular inspection. For this reason, the researchers in Munich also collaborate with Fahrzeugsystemdaten Technik GmbH (FSD) in Dresden, to which all Technical Inspectorates are affiliated. The FSD develops the standards that must be followed in all vehicle inspections.
An important source of evidence
Most accidents are not attributable to technical faults. In 70 to 80% of cases, the human factor is the crucial element: Alcohol and excess speed are the primary causes of fatal accidents. There has also been an inexorable rise in the frequency of collisions caused by medical factors. “In 39% of cases involving male drivers over the age of 65, acute health crises – such as a heart attack at the wheel – precipitated the accident,” Hell points out.
These data are all being incorporated into SUD, and the database will be continually extended in the coming years. This will further increase its usefulness as a tool for Technical Inspectorates and other parties. Moreover, the database serves as an indispensable source of evidence when it comes to persuading the auto industry to improve the safety of their products – irrespective of whether this involves enhancing the structural stability of vehicles or developing driver assistance systems that can sense a loss of control by the driver, apply the brakes and bring the vehicle safely to a halt at the side of the road. “Although it is true that cars have become much more stable and much safer, there is plenty of room for further improvement. Unfortunately, it often takes a great deal of convincing to get people to take the necessary steps,” says Wolfram Hell. “Measures taken to enhance safety are expensive and it is often difficult to convey to people that they really make a difference. Of course it is a good thing when a model passes a rigorous crash test, but it is not enough. The sad thing is that one realizes how much can still be done only when one analyzes real accidents and draws the proper conclusions.”
The 54-year-old, who is also a member of the German Advisory Council on Transportation Safety (Deutscher Verkehrssicherheitsrat) has learned to live with the fact that his findings are not always received with open arms by the auto industry. It is a risk that he is willing to take: “Our research is not an end in itself. We don’t do it just to fill up library shelves. We want to make things better, we want to save lives.”