Differences in glance behavior between drivers using a rearview camera, parking sensor system, both technologies, or no technology during low-speed parking maneuvers

Joint Effect of Heavy Vehicles and Diminished Light Conditions on Paediatric Pedestrian Injuries in Backover Crashes: A UK Population-Based Study

Backover crashes cause considerable injuries especially among young children. Prior research on backover crashes has not assessed the joint effect of heavy vehicles and diminished light conditions on injuries. By analysing the United Kingdom STATS19 crash dataset from 1991 to 2020, this study focused on backover crashes involving paediatric cyclists or pedestrians aged ≤17 years and other motorised vehicles. By estimating the adjusted odds ratio (AOR) of multiple logistic regression models, pedestrians appeared to have 82.3% (95% CI: 1.78-1.85) higher risks of sustaining killed or serious injuries (KSIs) than cyclists. In addition, casualties involved in backover crashes with heavy vehicles were 39.3% (95% CI: 1.35-1.42) more likely to sustain KSIs than those involved in crashes with personal cars. The joint effect of heavy vehicles and diminished light conditions was associated with a 71% increased probability of sustaining KSIs (AOR = 1.71; 95% CI: 1.60-1.83). Other significant joint effects included young children (aged 0 to 5 years) as pedestrian (AOR = 1.92; 95% CI: 1.87-1.97), in diminished light conditions (AOR = 1.23; 95% CI: 1.15-1.31), and with heavy vehicle (AOR = 1.37; 95% CI: 1.28-1.47).

Technology Developments and Impacts of Connected and Autonomous Vehicles: An Overview

The scientific advancements in the vehicle and infrastructure automation industry are progressively improving nowadays to provide benefits for the end-users in terms of traffic congestion reduction, safety enhancements, stress-free travels, fuel cost savings, and smart parking, etc. The advances in connected, autonomous, and connected autonomous vehicles (CV, AV, and CAV) depend on the continuous technology developments in the advanced driving assistance systems (ADAS). A clear view of the technology developments related to the AVs will give the users insights on the evolution of the technology and predict future research needs. In this paper, firstly, a review is performed on the available ADAS technologies, their functions, and the expected benefits in the context of CVs, AVs, and CAVs such as the sensors deployed on the partial or fully automated vehicles (Radar, LiDAR, etc.), the communication systems for vehicle-to-vehicle and vehicle-to-infrastructure networking, and the adaptive and cooperative adaptive cruise control technology (ACC/CACC). Secondly, for any technologies to be applied in practical AVs related applications, this study also includes a detailed review in the state/federal guidance, legislation, and regulations toward AVs related applications. Last but not least, the impacts of CVs, AVs, and CAVs on traffic are also reviewed to evaluate the potential benefits as the AV related technologies penetrating in the market. Based on the extensive reviews in this paper, the future related research gaps in technology development and impact analysis are also discussed.

Relationship between pedestrian detection specifications of parking sensor and potential safety benefits

Measures to protect vulnerable road users during low-speed maneuvers are required. For example, systems that use cameras to display the vehicle's rearview are popular. However, some vehicles are difficult to equip with a rear view camera system. To avoid a crash when driving in reverse, it is also effective to identify the presence of pedestrians via an audible warning using a device (e.g., clearance sonar). It may be cheaper to install than a rearview camera system. Installation cost is also important for the spread of equipment that reduces a crash. It is necessary to clarify the minimum specifications that balance cost and reduce crashes. Device specifications (e.g., detection distance and response delay) may affect the crash reduction rate. There should be a detection distance required for the sonar to have the same crash reduction effect as the rear view camera system. Thus, in this study, we conducted experiments and obtained data about how a vehicle moves and driver reactions to audible warnings when driving in reverse. Based on the acquired data, a numerical simulation was performed to determine whether a driver could avoid a crash under various circumstances. As a result, it was shown that the clearance sonar must have a detection distance of 0.8 m or more to expect the same effect as a rearview camera system. In other words, to expect sonar to have the same performance as a rearview camera, a detection distance of at least 0.8 m should be set as a specification.

Pedestrian Detection During Vehicle Backing Maneuvers Using Ultrasonic Parking Sensors

Ultrasonic parking sensors are an active technology designed to alert drivers to the presence of objects behind their vehicle but not the presence of a human. The purpose of this study was therefore to ascertain if these sensor systems can successfully detect a human subject. We accordingly conducted experiments using four vehicles equipped with both rear-facing center and corner ultrasonic parking sensor systems to determine the detection distance between the vehicle and a 1-m tall, 75-mm diameter pipe, a child, an adult woman, and an adult man. The detection of human subjects was evaluated under front-facing and side-facing conditions behind each vehicle. The results indicate that for a front-facing and side-facing child, the center sensor detection distances were 50-84% and 32-64%, respectively, shorter than that of the pipe. For front-facing and side-facing adults, the center sensor detection distances were just less than or roughly equivalent to that of the pipe at 89-102% and 78-97%, respectively. A similar trend was seen for the corner sensors. Notably, under the side-facing condition, the sensor detection distances were slightly shorter for all subjects than under the front-facing condition. These results reveal that ultrasonic parking sensor systems can not only detect objects but also humans, indicating that ultrasonic sensors are an available countermeasure to prevent backover accidents involving pedestrians. To address the shorter detection distance of children, a combination of ultrasonic parking sensors with other systems, such as backup cameras, may be more effective for avoiding backover collisions.

Effects of rearview cameras and rear parking sensors on police-reported backing crashes

OBJECTIVE

The objective of this study was to examine the effectiveness of rearview cameras, rear parking sensors, and both systems combined in preventing police-reported backing crashes.

METHODS

Negative binomial regression was used to compare rates of police-reported backing crash involvements per insured vehicle year in 22 U.S. states during 2009-2014 between passenger vehicle models with backing technologies and the same vehicle models where the optional systems were not purchased, controlling for other factors affecting crash risk. Rearview cameras were examined from four automakers, rear parking sensors from 2 automakers, and both systems combined from a single automaker.

RESULTS

Rearview cameras reduced backing crash involvement rates by 17%. Reductions were larger for drivers 70 and older (36%) than for drivers younger than 70 (16%); however, estimates for older and younger drivers did not differ significantly from one another. The Buick Lucerne's rear parking sensor system reduced backing crash involvement rates significantly by 34%, but the reduction for Mercedes-Benz vehicles fit with a sensor system was small and not statistically significant. When averaged between the 2 automakers, effects were significantly larger for drivers 70 and older (38% reduction) than for drivers younger than 70 (1% increase); effects were significant for older but not younger drivers. Backing crash involvement rates were 13% lower among Mercedes-Benz vehicles with a rearview camera and parking sensors than among vehicles without, but this finding was not significant.

DISCUSSION

Rearview cameras are effective in preventing police-reported backing crashes. Effects of rear parking sensors are less straightforward; it is unclear whether the Buick Lucerne system's benefits are due to the older age of its drivers, characteristics of the vehicle or system, or a combination. Systems may be especially beneficial to older drivers who might have limitations that make backing challenging. Although effect estimates did not differ significantly between older and younger drivers for both system types, the magnitude of the differences was large and the pattern of results was consistent across 6 of the 7 systems examined. When rear visibility systems become required equipment on new passenger vehicles in 2018, rearview cameras can be expected to prevent 1 in 6 backing crashes reported to police that involve equipped vehicles.