This study aimed to explore how pedestrians´ safety perception concerning the built environmental characteristics can assist in designing a safer built environment in an urban area in Mexico. The s...

Objective: Frontal impact chest protection in European cars has been highlighted as an area where possible improvements could be made. The chest is particularly vulnerable in older occupants whose numbers are forecast to increase significantly in the coming decades. This study aimed to provide some direction to areas for possible improvements in frontal crash chest protection. Methods: Real-world crash injury data were interrogated, focusing on cars with current restraint components. The research examined belted front seat occupants in frontal impacts where airbags, pretensioners, and load limiters were present. Results: The chest was the most often injured body region at Abbreviated Injury Scale (AIS) 2+, 3+, and 4+ injury levels. The rate of AIS 2+ and AIS 3+ chest injuries was highest among elderly occupants and lowest among young occupants, and elderly occupants sustained proportionally more severe chest injuries in low/moderate-speed impacts compared to young and middle-aged occupants. However, it should be noted that rates of AIS 2 chest injury were also significantly higher for middle-aged occupants compared to the young. The front passenger seat was shown to be more often associated with significant chest injury than the driver seat. The higher proportion of elderly female occupants was postulated as a reason for this. Skeletal injury was the most frequent type of AIS 2+ chest injury, and the rate of injury for elderly occupants with such injuries was higher than that for young and middle-aged occupants. With the increase in the number of rib fractures, the risk of pulmonary complications and organ injuries tended to increase. The major cause of chest injury was identified as restraining loads transmitted to the chest via the seat belt. The absence of intrusion in the majority of cases suggests an opportunity for the restraint system to better manage the crash pulse, not only for elderly occupants but for those who are middle-aged as well. Conclusions: This study shows the necessity for safety interventions, through new vehicle crashworthiness systems, to improve chest protection, especially for middle-aged and elderly car occupants. Deployment of appropriate injury risk criteria, use of an appropriate dummy thorax, development of a low-energy restraint test, and the development of more adaptive restraints have been discussed as possible solutions to the problem.

Globally and regionally, there is an increasing impetus to electrify the road transport system. The diversity and complexity of the road transport system pose several challenges to electrification in sectors that have higher energy usage requirements. Electric road systems (ERS) have the potential for a balancing solution. An ERS is not only an engineering project, but it is also an innovation system that is complex and composed of multiple stakeholders, requiring an interdisciplinary means of aligning problems, relations, and solutions. This study looked to determine the political, economic, social, and technical (PEST) factors by actively engaging UK stakeholders through online in-depth and semi-structured discussions. The focus is on dynamic wireless power transfer (DWPT) due to its wider market reach and on the basis that a comprehensive review of the literature indicated that the current focus is on the technical challenges and hence there is a gap in the knowledge around application requirements, which is necessary if society is to achieve its goals of electrification and GHG reduction. Qualitative analysis was undertaken to identify factors that are critical to the success of a DWPT system. The outcome of this study is knowledge of the factors that determine the function and market acceptance of DWPT. These factors can be grouped into six categories: vehicle, journey, infrastructure, economic, traffic and behaviour. These factors, the associated probability distributions attributable to these factors and the relations between them (logic functions), will form the basis for decision making when implementing DWPT as part of the wider UK electric vehicle charging infrastructure and hence support the ambition to electrify all road transport. The results will make a significant contribution to the emerging knowledge base on ERS and specifically DWPT.

Objective: To determine whether varying the seat belt load limiter (SBL) according to crash and occupant characteristics could have real-world injury reduction benefits in frontal impacts and, if so, to quantify those benefits. Methods: Real-world UK accident data were used to identify the target population of vehicle occupants and frontal crash scenarios where improved chest protection could be most beneficial. Generic baseline driver and front passenger numerical models using a 50th percentile dummy were developed with MADYMO software. Simulations were performed where the load limiter threshold was varied in selected frontal impact scenarios. For each SBL setting, restraint performance, dummy kinematics, and injury outcome were studied in 5 different frontal impact types. Thoracic injury predictions were converted into injury probability values using Abbreviated Injury Scale (AIS) 2+ age-dependent thoracic risk curves developed and validated based on a methodology proposed by Laituri et al. (2005). Real-world benefit was quantified using the predicted AIS 2+ risk and assuming that an appropriate adaptive system was fitted to all the cars in a real-world sample of recent frontal crashes involving European passenger cars. Results: From the accident data sample the chest was the most frequently injured body region at an AIS 2+ level in frontal impacts (7% of front seat occupants). The proportion of older vehicle front seat occupants (>64 years) with AIS 2+ injury was also greater than the proportion of younger occupants. Additionally, older occupants were more likely to sustain seat belt–induced serious chest injury in low- and moderate-speed frontal crashes. In both front seating positions, the low SBL provided the best chest injury protection, without increasing the risk to other body regions. In severe impacts, the low SBL allowed the driver to move dangerously close to the steering wheel. Compared to the driver side, greater ride-down space on the passenger side gave a higher potential for using the low SBLs. When applying the AIS 2+ risk reduction findings to the weighted accident data sample, the risk of sustaining an AIS 2+ seat belt injury changed to 0.9, 4.9, and 8.1% for young, mid, and older occupants, respectively, from their actual injury risk of 1.3, 7.6, and 13.1%. Conclusions: These results suggest the potential for improving the safety of older occupants with the development of smarter restraint systems. This is an important finding because the number of older users is expected to increase rapidly over the next 20 years. The greatest benefits were seen at lower crash severities. This is also important because most real-world crashes occur at lower speeds.

Objective: Current European restraint systems may not realize their full protection potential in real-world frontal crashes because they are highly optimized for specific conditions. This research sought to quantify the potential benefit of adapting seat belt load limit thresholds to a wider range of occupant and crash characteristics. Methods: Numerical simulations using Hybrid III dummies were conducted to determine how varying load limiter thresholds could affect occupant kinematics and injury outcome in frontal impacts. Occupant–compartment models were developed with a restraint system consisting of a frontal airbag and a 3-point belt with retractor, buckle pretensioner, and load limiting at the shoulder. Load limiting threshold was varied in 5 frontal impact scenarios, covering as wide a range of real frontal crash conditions as possible. The simulated thoracic injury risks were converted into injury probability values using Abbreviated Injury Scale (AIS) 2+ age-dependent thoracic risk curves. These values were then applied to a British real-world frontal impact sample to determine the injury reduction potential of optimized load limiting, taking into account occupant seating position, impact scenario, occupant size, and occupant age and assuming that an appropriate adaptive system was fitted to all cars. Results: In low-severity impacts, a low load limit provided the best chest protection, without increasing risk to other body regions, for both the 50th and 95th percentile dummies in both front seating positions. In high-severity impacts, the low limit was not recommended because it allowed the driver dummy to move into close proximity with the vehicle interior, although there appeared to be some benefit of lower load limiting for the 50th percentile front passenger dummy, due to the increased ride down space in that seating position. Adapting the load limit showed no injury reduction potential for 5th percentile drivers. Utilizing the best load limit threshold in real-world crashes could reduce the number of occupants with AIS 2+ chest injuries from belt loading from 377 to 251 (a 33% reduction), correspondingly reducing the number of occupants with AIS 2+ chest injuries (from all sources) in the whole frontal impact population from 496 to 370. This is a reduction in injury rate from 6.4% to 4.8%. Conclusions: The concept of an adaptive load limiter shows most promise in low-speed frontal crashes where it could lower the AIS 2+ chest injury risk for most front seat occupants, except the smallest of drivers. Generally, adaptive limiters show less potential effectiveness with increased crash severities. Overall, an intelligent adjustment of load limiting threshold could result in a reduction of at least a third of front seat occupants with AIS 2+ chest injuries associated with restraining loads and an overall reduction in AIS 2+ chest injury rate in frontal crashes from 6.4% to 4.8%