EUROPEAN EXPERIMENTAL VEHICLES COMMITTEE: WORKING GROUP 10 ON PEDESTRIAN PROTECTION (1991). Development of a Head Impact Test Procedure for Pedestrian Protection. Proceedings of the Thirteenth ESV Conference, Paris, November 1991. (K. P. Glaeser)

This study compares crash test dummy parameter values from sled tests with real-life accident data in order to evaluate the applicability of crash test methods to assess the risk of whiplash injury in rear-end impacts.

4.a. Evaluation of Seat Performance Criteria for Rear-end Impact Testing: BioRID II and Insurance Data

Johan Davidsson (JD) presented a common study of Chalmers and Folksam on the evaluation of seat performance criteria based on insurance data (WCWID-01-03). The presentation was an update of GTR7-14-02. The study was performed within the EEVC work programme by EEVC WG12 (see report WCWID-01-09):

Approach for the study is to compare claim rates for different seats in the Folksam insurance data with BioRID II metrics from tests for the same seats.

The focus is on neck injury and very few thoracic or lumbar spine injuries/claims are contained in the Folksam database.

Two risk levels:
1. Symptoms for more than one month in case of initial symptoms
2. Permanent medical impairment in case of initial symptoms (with no financial incentive to claim this level of symptom)

The Chalmers/Folksam/EEVC study uses 150 cases per seat (IIHS used a minimum group size of 30 cases, which may explain the weak correlations that they reported).

In Sweden, the risk for a given vehicle has reduced over 10 years, indicating that the assessment of injury by the medical profession has become stricter. This has been compensated for in the study by normalising to the 2005 risk level.

The risk for different seats cf. the NIC was shown as an example. Philippe Petit (PP) asked if the differences were tested for significance, because the range is quite small. This was not the case. Norbert Praxl (NP) asked if confounding factors were controlled like e.g. delta-v?

JD replied that there was no information on delta-v, but ensured that the groups were not very light or very heavy vehicles. The Volvo and Saab had a step-change in seat design on a
vehicle platform of very similar mass and structure.

Koshiro Ono (KO) asked whether the patients’ medical records were re-reviewed by the study in order to confirm the diagnosis and the severity of WAD. This was not the case, but for the permanent injury rating there is a considerable effort that the patient has to go to in order to be classified, with little reward.

Overall, NIC showed the best correlation with risk, both at the symptoms > 1 month and the permanent medical impairment levels. OC-T1 x-axis relative displacement and L1 x-axis acceleration correlated with long-term injury risk. Neck extension and T1 x-axis acceleration may be candidates, but appear to be sensitive to inclusion or not of outliers.

Limitations of the study include:
• Changes to the dummy over time
• Changes since the seats in the study were tested
• Correlation coefficients were maximum 0.72.

PP noted that there is a very strong assumption that the pulse is the same over time, even for an identical vehicle. In France, it was observed that the average speed of fatal collisions
was increasing until automatic ticketing was introduced, when it dropped 5%. JD: 2009 pulses likely to be more severe than 1999, due to changes in the vehicle structures.

Agnes Kim (AK) noted that the study is based on Folksam data and that means Swedish drivers, who are more likely to sit in a ‘standard’ position than US drivers, who tend to have a
very poor, non-standard posture. BL: This is the data we need – the regulator can only assume that a driver is sitting in a good position with a correctly adjusted seat, and ensure that they are provided with a minimum level of safety in this case if they take this care. The seat-belt doesn’t protect you if you don’t wear it, but it is still required to be fitted. AK pointed out that in regulations to date we take due care to ensure that if an occupant is somewhat out of position they will still be protected, but the rear impact is somewhat different.

Annette Irwin (AI) asked whether the BioRID predicts that the risk is, as would be expected, lower in the heavier vehicles. JD replied that he can’t answer this question based on this data, but other studies have done this.

Part 3 of 3 of the EEVC report on the design and evaluation of the Q10 child dummy which is the latest extension to the new generation of child dummies called Q-dummies. The Q-dummies were developed to replace the P-dummies in the UN Regulation 44 and in consumer testing. EEVC Working Groups 12 (Biomechanics) and 18 (Child Safety) collaborated on joint research to evaluate the Q-Series and recommended that they replace the P-Series in UN Regulation 44.

Part 2 of 3 of the EEVC report on the design and evaluation of the Q10 child dummy which is the latest extension to the new generation of child dummies called Q-dummies. The Q-dummies were developed to replace the P-dummies in the UN Regulation 44 and in consumer testing. EEVC Working Groups 12 (Biomechanics) and 18 (Child Safety) collaborated on joint research to evaluate the Q-Series and recommended that they replace the P-Series in UN Regulation 44.

Part 1 of 3 of the EEVC report on the design and evaluation of the Q10 child dummy which is the latest extension to the new generation of child dummies called Q-dummies. The Q-dummies were developed to replace the P-dummies in the UN Regulation 44 and in consumer testing. EEVC Working Groups 12 (Biomechanics) and 18 (Child Safety) collaborated on joint research to evaluate the Q-Series and recommended that they replace the P-Series in UN Regulation 44.

November 1994 working paper from the European Enhanced Vehicle Safety Committee (formerly, European Experimental Vehicles Committee).

May 1996 presentation at the 15th ESV Conference held in Melbourne, Australia.

96-page EEVC WG17 working paper, updated from 1998.

Presentation from Mr Davidsson on behalf of EEVC (GTR7-06-09).

Progress update on a study to investigate the correlation between rear impact seat test results and Folksam insurance data for a range of vehicle models. Insurance data from 1995 to 2008 were used. Two risk measures were assessed:

• - symptoms > 1 month, and
• - risk of permanent medical impairment (it takes up to three years to establish this, so no data more recent than 2008 in the study).

Seat test data were from existing databases using BioRID II e and g, with two different H-point tools.

Results were reported for groups of seats from different vehicles in which the seat design was about the same. NIC, upper neck shear force (Fx, head rearward), and head-to-T1 angle gave the best correlation with risk of permanent injury in these preliminary results. It was noted that some seats show an opposite trend for some individual criteria, even for seats with markedly reduced risk. This was taken to show the need for multiple criteria.

It was noted that the analysis will be repeated later this year, when it is expected that there will be three times as many data available. Occupant gender will be controlled in the updated study( there should be enough data to do this). This study looks at the ability of a test with BioRID to discriminate between seats with different risk in the field [where drivers are of different size, gender, seating position, posture etc.]. Action Mr Davidsson to complete the study by the end of 2011, and to compare the results with the recommendations on criteria coming from biomechanical studies. Also to contact Dr Ono and discuss collaboration.

It was noted that R2 would not be expected to equal 1, as noted in the slide, but a low R2 still indicates that the parameter is a poor predictor of permanent injury. Also it is not clear that using several parameters with poor R2 will give a better overall prediction. Mr Frost noted that these issues will have to be discussed in future meetings.

It was noted that Nkm was recommended, in preference to the individual forces and moments because the individual forces and moments gave very low correlations. It was hypothesised that the variations in these individual parameters is masked when they are combined in the Nkm calculation.

Ms Meyerson summarised the US benefit cost analysis for the FMVSS 214 pole side impact rulemaking process (PSI-01-16).

Mr Langner presented a summary of the EEVC benefit cost analysis of side impact test procedures on behalf of EEVC WG13 and EEVC WG21 (PSI-01-17).

Ms Tylko asked if the EEVC analysis had weighted the serious injury costs to account for the higher cost of head injuries compared to other injuries. Mr Damm advised that the serious injury costs used in the EEVC analysis are average costs for all serious injuries.
Ms Tylko pointed out that it is important to account for the fact there is much less difference between fatal crash costs and serious injury crash costs for accident types, such as pole side impacts, where serious head injuries are more common.

Mr Langner advised the Informal Group that it was important to note that the costs of countermeasures were calculated in Euros from costs provided by the German car industry, while benefits were calculated in Pounds based on analysis of UK crash data. The cost benefit ratio could therefore fluctuate with the exchange rate, and the objective of the EEVC analysis was to establish the relative benefits and costs of alternative side impact test procedures, rather than true cost benefit ratios.

Mr Hogan noted that costs and benefits could vary substantially from one country to the next, and that the Informal Group should seek to establish cost and benefit estimates for a number of different countries. Mr Hogan also stated that industry will need to be approached to provide up to date cost estimates for different pole side impact test methods at an appropriate stage during the future work of the group.

Ms Meyerson presented a summary of the technical rationale for the US FMVSS 214 pole test (PSI-01-10).

Mr Langner presented a summary of the EEVC accident data analysis of side impacts with poles on behalf of EEVC WG13 and EEVC WG21 (PSI-01-11).

Although the US had determined oblique pole impacts to be the most common, and EEVC had determined perpendicular impacts to be the most common, it was noted by several members of the Informal Group that 9 and 3 o’clock (perpendicular) principal direction of force impact classifications have a range of ±15 degrees, and a 75 degree oblique pole impact is therefore exactly on the division between 2 and 3 o’clock, and 9 and 10 o’clock.

Mr Terrell presented a summary sheet of crash tests relevant to the activities of the Informal Group, and noted that Australia, Japan, and the US had provided details of crash tests conducted that could be useful for the development of a pole side impact GTR (PSI-01-12).

Mr Hogan asked the members of the Informal Group to provide details of any relevant crash tests they had conducted, or will conduct in the future, which might assist the pole side impact GTR development process.

Proposal to introduce in the Regulation new characteristics for a mobile deformable barrier.