| 1. |
- Jonsson, Jonathan, 1989, et al.
(författare)
-
The Effect of Advanced Automatic Collision Notification (AACN) on Road Fatality Reduction in Sweden
- 2015
-
Ingår i: Proceedings of the 3rd International Symposium on Future Active Safety Technology Towards Zero Traffic Accidents (FAST-zero 2015).
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper aims at estimating the effect of the Advanced Automatic Collision Notification (AACN) post–crash system on road fatality reduction in Sweden. The analysis was based on the Swedish Traffic Accident Data Acquisition (STRADA) database in combination with in-depth studies of fatal accidents. Logistic regression with backward selection was used to identify relevant variables and develop a statistical model. The variables ‘admission to trauma center’, ‘age’ and ‘injury severity’ were identified as significant and by applying the final model on fatalities in passenger cars the estimated fatality reduction due to AACN was calculated. AACN was estimated to potentially reduce road fatalities by 9.6% (95% CI = -0.1-18.4%)
|
|
| 2. |
- Lübbe, Nils, 1982, et al.
(författare)
-
Assessment of Integrated Pedestrian Protection Systems with Forward Collision Warning and Automated Emergency Braking
- 2015
-
Ingår i: 2015 IRCOBI Conference Proceedings - International Research Council on the Biomechanics of Injury. ; , s. 385-397
-
Konferensbidrag (refereegranskat)abstract
- Automated Emergency Braking systems reduce impact speeds, and consequently, injuries in car‐ to‐pedestrian impacts. The development of assessment methods for these systems has received considerable attention. Forward Collision Warning systems similarly aim at reducing impact speed, but have received less attention. Casualty cost reductions of several simplified but realistic Forward Collision Warning and Automated Emergency Braking systems were calculated using simulations and a modified AsPeCSS method. Automated Emergency Braking systems were assessed to result in approximately 25% casualty cost reductions. Forward Collision Warning effectiveness ranged from “no benefit” for an audio‐visual warning system with late activation, to a benefit of 25 % casualty cost reduction for an early activating warning system including an additional short brake pulse. As Forward Collision Warning seems to have the potential to reduce pedestrian casualties of the same magnitude as Automated Emergency Braking, the authors suggest including a Forward Collision Warning assessment in a modified AsPeCSS method to rate pedestrian protection of cars.
|
|
| 3. |
- Lübbe, Nils, 1982, et al.
(författare)
-
Drivers’ comfort boundaries in pedestrian crossings: A study in driver braking characteristics as a function of pedestrian walking speed
- 2015
-
Ingår i: Safety Science. - : Elsevier BV. - 0925-7535 .- 1879-1042. ; 75, s. 100-106
-
Tidskriftsartikel (refereegranskat)abstract
- Systems informing or warning a driver of an imminent collision with a pedestrian or automatically initiating braking have been introduced to the car market. One of the major challenges is to balance system performance against the possibility of undesired system activation. The distinction between desired and undesired system activation can be based on driver discomfort. In this study driver discomfort can be inferred from brake onset, which refers to the start of brake pedal depression, as the most intuitive way for a driver to resolve a conflicting situation. The influences of pedestrian walking speed on brake onset and brake deceleration levels were investigated in Toyota Motor Corporation’s high-fidelity driving simulator. One hundred and eight naive volunteers drove at a target speed of 30 km/h in an urban environment and were subjected to two animations of pedestrian crossing situations projected inside the driving simulator. The pedestrian speed was 1 m/s and 2 m/s. Time To Collision (TTC) at brake onset, one of the recorded quantities, might be a suitable measure for comfort zone boundaries as it is less affected by driving speed than other measures.Pedestrian speed was found to have a statistically significant influence on brake onset. For pedestrian speeds of 1 m/s, 90% of drivers braked before 2.6 s TTC. For 2 m/s this value was 2.2 s. These values can be used to differentiate between desired and undesired system activation in the design of an "unjustified system response" test in the assessment of pedestrian safety systems.
|
|
| 4. |
- Lübbe, Nils, 1982
(författare)
-
Integrated Pedestrian Safety Assessment: A Method to Evaluate Combinations of Active and Passive Safety
- 2015
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Pedestrian road casualties are a major concern in many countries. Vehicle safety systems attempt to reduce casualties, and the accurate assessment of such systems is therefore essential. Passive safety assessment is well established, and additional active safety assessment has recently emerged. However, assessment methods accounting for the interaction between active and passive safety do not exist in today’s regulatory or consumer testing. An integrated safety assessment can help reduce pedestrian casualties more effectively and efficiently by taking information gained through active safety assessment into consideration and modifying the passive safety assessment accordingly.This research develops an integrated pedestrian safety assessment method and demonstrates its use in assessing combinations of passive safety and the active systems of Automated Emergency Braking (AEB) and Forward Collision Warning (FCW).Firstly, a method was developed that predicts causality costs for a vehicle using data from passive safety and AEB evaluations. Casualty costs were then compared for vehicles with good, average or poor Euro NCAP passive safety ratings in combination with an A-pillar airbag and an AEB system. The results show that the AEB system has a safety benefit broadly equivalent to increasing the Euro NCAP passive safety rating from poor to average or average to good, and that the estimated benefit of the A-pillar airbag exceeded that of the AEB system.Secondly, the method was extended to assess FCW systems. Data to model driver reactions required for the FCW assessment were obtained in a volunteer study. Applying this method for different types of FCW systems showed that such systems can, but do not necessarily, provide benefits similar to those of AEB systems. An early activating FCW system with a haptic (brake pulse) warning interface was as effective as an AEB system in reducing casualty cost.These assessments of AEB and FCW systems measure True Positive performance, which is, broadly speaking, the performance of an activated system in situations in which activation was needed. Additional False Positive requirements are proposed to ensure that active safety systems are not activated too early; a threshold of what could be considered too early was developed from the quantification of driver comfort boundaries in volunteer studies. The integrated assessment method proposed has the benefit of estimating overall safety performance with a single indicator, casualty cost, making results for different vehicles easily comparable. Furthermore, as the method aims at a realistic assessment of a vehicle’s ability to protect pedestrians, all body regions and injury severities, as well as impact kinematics, all relevant impact speeds, and their interdependencies are taken into account making this the most complete method currently developed. However, since the method relies on the testing of a vehicle’s active safety systems in representative scenarios, and on the testing of its passive safety with existing impactor tests, limitations of these existing test procedures will necessarily have an impact.It is suggested that the proposed integrated pedestrian safety method be implemented in consumer testing to assess the total benefit offered by any combination of active and passive safety technology. In addition, findings suggest that testing for active safety should be expanded to FCW systems and, furthermore, that False Positive tests should be implemented. In the test scenarios already in use for assessment of speed reductions, AEB and FCW system activation before comfort boundary timing should be discouraged. On implementing these proposals, assessment would more accurately reflect the total safety benefit offered by different systems and therefore aid the development and proliferation of the most effective and efficient pedestrian safety systems.
|
|
