The demographical change is reflected in the population of road users. In fact, today’s older people are driving further (changed behaviour) and more often than previous cohorts. Furthermore, in the United States Kent et al. (2003) foresaw 50,000 additional serious injuries between 1966 and 2012 only due to this demographic change. Although in the future the older drivers will be more vital and experienced, the increase of people aged 75 and above, the increase of licence rates for older drivers and the increase on the mobility for these drivers will lead to a further increase of fatalities among older drivers. In addition, elderly road users who mainly take part in traffic by walking (as pedestrians) or cycling (as cyclists) are expected to have an increased need and desire for mobility. This trend will even be strengthened due to the introduction of new transport means such as e-bikes.
In many aspects, the age of the road users is one of the most differentiating factors when analysing accident data. Ageing has an important influence on physical ability and frailty making elderly one of the most vulnerable road user groups in any mean of transport.
The elderly will be considered as users of different road transport modes: (1) Car occupants; (2) Pedestrians, Cyclists, e-cyclists and (3) Other means of transport identified as preferred for this group of road users.
As shown in Figure 1 the modes of transport for the elderly will be assessed through (1) Accident studies and modal split; (2) Biomechanics; (3) Tools and procedures and (4) Influence of active safety measures. While results of accident studies and the impact of active safety measures will be mainly derived from latest projects, the focus of the SENIORS project will be set on the development of a deeper understanding of the biomechanics of elderly road users (by consideration of all main transport modes) and the development and refinement of test tools and procedures. The dissemination part of the project will enable discussions with stakeholders and finally accelerate the implementation of the results.
The main goal of SENIORS project is to improve the safe mobility of the elderly, including obese, using an integrated approach and real-based knowledge that includes the main modes of transport as well as the particularities of this vulnerable road user group
SENIORS will investigate and assess the injury reduction that can be achieved through innovative tools and safety systems targeting the protection of the elderly as car occupants and external road users (road users who are outside of a vehicle such as pedestrians, cyclists, e-bike riders). It is expected that the safety improvement of the main modes of transport used by the elderly will impact positively the safety of the other modes such as public transportation and motorcycles.
In order to exploit the capabilities of modern safety systems fully, this project aims to have a short term impact in the elderly road user safety by:
- Improving the protection of elderly road users as VRU in an integrated approach under consideration of the most relevant transport modes.
- Identification of the differences in dynamics of different road user age groups in the pre-crash and crash phase.
- Identification of anthropometric and injury mechanism peculiarities of elderly, including obese people, compared to younger people.
- Development and optimisation of test tools, procedures and assessment methods with special regard to elderly and obese users.
- Transfer of knowledge and results through cooperation with regulatory, consumer and insurance entities.
To identify the most common accident scenarios and injury information focussing on pedestrians, bicyclists or e-bikes, car occupants but also including other means of transport such as bus occupants, two different types of accident data will be analysed: (1) in-depth accident data and (2) macro statistical accident data. For the first one, the GIDAS, the RAIDS and the CIREN databases will be consulted. For macro statistical information, different national databases from European countries will be analysed as well as data from merged European accident data sources (e.g. CARE database). In addition, data from hospitals will be studied to gain additional information about injuries sustained to elderly (and obese) people who have been involved in road traffic accidents, also by consideration of further segmentations of age groups (e.g. 65-70, 71-80, 90+ years). To conclude the overview, studies from the field of traffic psychology will be considered which show up the needs of elderly and specify the physical limitations older people have as traffic participants (e.g. frailty, worse reaction times etc.). Further, the behaviour of elderly in road traffic will be investigated. This will include e.g. mobility studies and particular issues such as changes to the behaviour as car occupant (e.g. vehicle selection, sitting out of position, use of additional seat cushions) and to the behaviour as a pedestrian / cyclist (e.g. negligence, road crossing attitudes, body balance loss, usage of walking aids).
Height, weight, geometrical dimensions, bone characteristics and posture habits will be studied to assess the effectiveness of the existing test tools and to develop a basis for new developments of or further modifications to existing dummies or impactors.
The expected dynamic performance of humans in impact events will also be reviewed. This will build on existing knowledge to identify traits and performance requirements that are specific to older occupants. Additional novel information is also to be generated through volunteer work.
The level of injury tolerance per body region will be studied based on an extensive literature review. This work will be supported by simulations with age-specific human body models. The combination of this information with the injury causation data obtained from the previous accident data analysis will enable the development of age-specific injury risk curves (IRC) and additional IRC for important body regions which are neglected in current test and assessment procedures.
The current adult crash test dummies cover a 95th male, a 50th male and a 5th female but none of those considers age-related differences. The physiological study will provide the needed input to assess the conformity of these dummy specifications to older road users in terms of weight, height and shape. Additional issues such as resistance and positioning will also be studied. However, the study of the crash test dummies will not suffice as it doesn’t cover walking or cycling being two of the main means of transport for the elderly. Therefore, the suitability of the current pedestrian impactors to assess elderly protection will also be studied considering the developed injury risk assessments and accident studies carried out in previous activities of the project.
Current adult pedestrian impactors represent the body regions head, thigh and leg of a 50th male. However, the development of the vehicle fleet in the past decades led to different accident scenarios involving different pedestrian body regions and different injury causing parts of the vehicles. Besides, the impact of active safety on vehicle to pedestrian collisions in terms of impact kinematics and impact parameters, as studied in the FP7 project AsPeCSS, has to be taken into consideration. New and modified test tools and procedures will enable a better and more effective protection of vulnerable road users leading to a higher extent of injury mitigation in case of an impact.
The current systems are developed taking into account the existing test tools and therefore are not adapted to the elderly users. This is reflected in the fact that the elderly car occupants have the highest rate of chest injuries which are usually related to the interaction with the restraint system. In fact, there is room for improvement in frontal impact for elderly in relatively low speed collisions. Systems designed to make full use of the ride-down space at 64 km/h can be too stiff for older occupants and not using all the ride-down space improvements could result from using load limiter that adapted to the collision severity (for instance).
In the case of pedestrians and other external road users, possible modifications to the current test tools and procedures will be assessed, including the evaluation of the suitability of a thoracic impactor.
Further, changes due to the introduction of active safety systems in the vehicle fleet will be investigated by literature review and current test results as well as system’s real-world benefits. The information gathered will be considered in the overall impact assessment.
It has been previously pointed out that further research is needed to define injury risk predictors based on age-related parameters, especially for the elderly. The current project will not only compile the relevant information in terms of biomechanics studies and accident data but will fill this gap providing an adapted assessment covering a wider range of road users. In fact, it will include the assessment of the protection of a type of road user that will be more present on the European roads in the forthcoming years.
SENIORS will contribute to the achievement of the European policy objective of halving road deaths by 2020, and, in the longer term, to the Transport White Paper’s “Vision Zero” objective by delivering the following main (exploitable) results:
- Test and assessment methods for the evaluation of safety systems adjusted to protect a wide range of occupants in particular including the vulnerable elderly road users (car occupants, pedestrians and cyclists). Exploitation will take place on the one hand by test houses (TRL, BAST, IDIADA) via direct services offered to consumer information providers such as Euro NCAP and directly to the car industry. On the other hand car manufacturers and suppliers (Ford, FIAT, Autoliv) will exploit the results in terms of performance requirements / design targets for designing and implementing safety systems that offer improved protection.
- Test tools / equipment consisting of add-ons to existing tools like the THOR-M dummy and FlexPLI impactor. The exploitation will mainly take place in terms of sales via the test equipment provider (HIS).
- Increased equipment fitment rate of advanced safety systems (restraint systems for car occupant and pedestrian safety systems for pedestrians and cyclists) that offer protection to wider ranges of traffic participants and accelerated market introduction of new technologies. The exploitation will mainly take place via the car manufacturers and suppliers (Ford, FIAT, Autoliv) as well as by consumer information providers such as Euro NCAP and age-specific associations such as the Age platform Europe.
- Increased knowledge at the end user level (vehicle buyer) about the functionality and the benefits of advanced vehicle safety systems and the need to address protection of elderly car occupants thereby pushing the market demand of such safety systems. The exploitation will mainly take place via the car manufacturers (Ford, FIAT) as well as by consumer information providers such as Euro NCAP and age-specific associations such as the Age platform Europe.
- Increased knowledge at the research level (All partners), providing e.g. new information on the diverse injury patterns of the elderly, adapted injury risk curves and on similarities and differences on biomechanical level between younger and older people (incl. obesity).