Know-how saves lives. The Volvo Cars accident research team has therefore investigated more than 36,000 accidents over a period covering 35 years. Recently, Volvo Cars has also developed a research model and methodology for predicting the chain of events before and during a collision. The method helps to evaluate the effectiveness of new preventive safety systems such as Collision Warning with Auto Brake and City Safety.
The method is an extension of the traditional traffic accident research which has focused on the actual collision and its consequences. Volvo Cars has now extended the research and made it possible to go back in time from the crash and study the chain of events that led to the accident.
"Real-life safety is the key to our safety philosophy. When it comes to preventive safety, our research and technical development focus on areas where new technology can achieve significant results in real-life traffic. Focusing on the crucial moments before the crash helps us determine the right priorities," says Jan Ivarsson, Senior Manager, Safety Strategy & Requirements at Volvo Cars.
Presented in 2006
Volvo's enhanced research model was presented at the SAE 2006 World Congress at the beginning of 2006. The methodology is applicable to a number of types of accident, but is exemplified in the report by one of the most common types of accident in heavy traffic; a rear-end impact. The report shows the potential for calculating and evaluating the preventive safety effects of an auto brake system.
Combination of accident statistics, detailed studies, and reconstructions
The model is based on Volvo's many years of work of examining and following up actual accidents involving Volvo cars. The database contains comprehensive statistics of car accidents and their consequences.
In order to extend the analysis to the chain of events that happens moments before the collision, Volvo Cars has now supplemented its own statistics with external detailed studies and reconstructions of chains of events.
"The more detailed information enables us to give a more complete picture of the circumstances surrounding the situation that can lead to a traffic accident," says Jan Ivarsson. "We can add information about what has happened prior to the collision: speed, how the car has been handled, and what has led to the accident."
Based on the consolidated information, Volvo Cars has developed a research and presentation model in order to provide a clear picture of the circumstances before and at the moment the collision occurs.
"With this knowledge as a base, we can, under given circumstances, predict the chain of events in an accident, and can also calculate the risk of it leading to serious injuries," says Jan Ivarsson.
Possible to calculate the effect of an autonomous braking system
Using this prediction model as a starting point, Volvo Cars has calculate the effect of an auto brake system that reduces the colliding car's speed when a rear-end collision is imminent. The method makes it possible to evaluate different system settings. The results show how a significant proportion of collisions and injuries can be avoided when the auto brake system is activated.
"This helps us to fine-tune the system so we get the most suitable level of auto braking in critical situations," says Jan Ivarsson.
Safer motoring also for other road-users
The prediction method, with a combination of its own traffic statistics and external detailed studies, has opened the door to a more complete analysis of the accident situation and the circumstances surrounding it.
"By looking farther ahead and focusing even more on preventive safety measures, we can contribute to safer motoring, not only for Volvo drivers and their passengers but also for other road users," concludes Jan Ivarsson.
Started in the 1960s
The Volvo Cars accident research team can trace its roots back to the 1960s.
A few years after Volvo engineer Nils Bohlin invented the three-point safety belt and Volvo Cars had introduced this safety feature as standard in the front seats of all its models, a comprehensive study was launched into the injury-reducing effects of the car safety belt.
This survey, which was carried out in 1966, encompassed every accident in Sweden involving
a Volvo over a period of one year.
The results indicated that the safety belt had reduced injuries by 50 per cent.
Volvo immediately realised that insight and understanding of what actually happens to the vehicle and its occupants in a collision are invaluable sources of information in helping to shape future product development. A decision was therefore taken in 1970 to establish an in-house accident research team. This has remained in operation ever since.
"The need for experience from real-life accidents has not decreased in the intervening years," says Jan Ivarsson "even though we have obviously refined and improved our working methods over the years."
Depth and breadth
Volvo Cars' accident researchers work both in-depth and across a broad spectrum. In-depth studies of individual accidents provide multi-faceted knowledge about the complicated mechanisms involved in various accident scenarios, about how the car's protective systems function in real life and about the injuries suffered by the car's occupants.
In parallel, the collection of statistics from a wide range of sources provides the knowledge needed to monitor the probability of a given type of accident occurring in the first place. In this way, Volvo Cars can determine invaluable prioritisations in the development of new cars.
In order to obtain correct knowledge about what actually happened in a given accident, it is necessary to perform an immensely thorough investigation at the accident site itself.
On the move to the accident
Every time a serious accident involving a Volvo takes place within a 100 kilometre radius of Gothenburg on Sweden's west coast, the research centre's home base, the accident research team is notified by the SOS emergency response service, no matter what time of day or night.
At least one person from Volvo visits the accident site. If possible, the police delay removal of the cars involved until after Volvo's technicians arrive.
The technicians carry out a thorough investigation which is documented with measurements and photographs. Interviews are carried out with the police, witnesses and, if possible, the drivers and passengers involved.
After this investigation, the car is transported to Volvo's Safety Centre for further in-depth investigation.
Additional valuable information is gathered while all this is going on, for example relating to the car's occupants and their injuries.
When all this information is available, the material is analysed by personnel from the Safety Centre, the relevant engineering departments and medical experts.
The study of interesting situations - for instance high-speed accidents - can include both a thorough analysis of the actual accident at the scene itself and a reconstruction of the sequence in the crash-test laboratory.
Statistical analysis
The collation of statistics follows a different pattern. Here, the aim is to build up a statistical database of accident-related material which, after analysis, can be used to provide a clear picture of various factors, such as what type of personal injury occurs in a given accident scenario.
This takes place both through a follow-up of international statistics and through comprehensive investigations of the worst accidents in Sweden involving a Volvo.
Every year, about 50,000 accidents are reported to Volvo's Swedish insurance company, Volvia, which has about 15 assessment inspectors who investigate the most serious cases on behalf of the company.
All cases in which the repair cost exceeds a given level (currently equivalent to EUR 3,800) are investigated specially at the request of the accident research team.
All the documentation obtained, which includes photographs of the car's exterior and interior, is sent to the team on an ongoing basis. The process covers between 1500 and 2000 accidents per year.
This information serves as the starting-signal for comprehensive follow-up of the accident. Volvo's experts then gather background information from the accident site, the accident sequence and the resultant personal injuries.
Each accident is also followed up with documentation on the vehicles themselves as well as interviews with the car's occupants.
Foundations built on know-how
The accident research team's basic rule is: the more information it is possible to obtain, the better. The aim behind this process is to increase know-how about accidents and their consequences - knowledge that can subsequently be harnessed in product development.
"During all these years of dedication to safety, we have become expert at translating the team's research work into practical benefits - and at getting people to listen to us," comments Jan Ivarsson. "Because without the team's work, we would never succeed in making tomorrow's cars even safer."
Many of the safety systems introduced into Volvo cars over the years developed out of the knowledge generated by Volvo Cars' accident research team in its studies of real-life accidents.
"Looking at real-life accidents, why they happened and how the cars protected the occupants, gives us the opportunity to study how well our preventive and protective systems function - and they provide us with the basis for the development of future systems," explains Jan Ivarsson.
