Collision Reduction Research Articles

Effects of nine typical technologies for primary autonomous vehicles on road safety in China

The autonomous vehicle is profoundly changing the future of transportation safety. The reduction in collisions with different injury degrees and the savings of crash-related economic costs if nine autonomous vehicle technologies were promoted to be wildly available in China are evaluated. The quantitative analysis was divided into three main parts: (1) Calculate the technical effectiveness of nine autonomous vehicle technologies in collisions through a systematic literature review; (2) Apply the technical effectiveness to estimate the potential effects on avoiding collisions and saving crash-related economic costs in China if all vehicles had these technologies; and (3) Quantify the influence of current technical limitations in speed applicability, weather applicability, light applicability, and active rate on potential effects. Definitely, these technologies have different safety benefits in different countries. The framework developed and technical effectiveness calculated in this study can be applied to evaluate the safety impact of these technologies in other countries.

Window films increase avoidance of collisions by birds but only when applied to external compared with internal surfaces of windows.

Window collisions are one of the largest human-caused causes of avian mortality in built environments and, therefore, cause population declines that can be a significant conservation issue. Applications of visibly noticeable films, patterns, and decals on the external surfaces of windows have been associated with reductions in both window collisions and avian mortality. It is often logistically difficult and economically prohibitive to apply these films and decals to external surfaces, especially if the windows are above the first floor of a building. Therefore, there is interest and incentive to apply the products to internal surfaces that are much easier to reach and maintain. However, there is debate as to whether application to the internal surface of windows renders any collision-reduction benefit, as the patterns on the films and decals may not be sufficiently visible to birds. To address this knowledge gap, we performed the first experimental study to compare the effectiveness of two distinct window films when applied to either the internal or external surface of double-glazed windows. Specifically, we assessed whether Haverkamp and BirdShades window film products were effective in promoting the avoidance of window collisions (and by inference, a reduction of collisions) by zebra finches through controlled aviary flight trials employing a repeated-measures design that allowed us to isolate the effect of the window treatments on avoidance flight behaviors. We chose these two products because they engage with different wavelengths of light (and by inference, colors) visible to many songbirds: the BirdShades film is visible in the ultraviolet (shorter wavelength) range, while the Haverkamp film includes signals in the orange (longer wavelength) range. We found consistent evidence that, when applied to the external surface of windows, the BirdShades product resulted in reduced likelihood of collision and there was marginal evidence of this effect with the Haverkamp film. Specifically, in our collision avoidance trials, BirdShades increased window avoidance by 47% and the Haverkamp increased avoidance by 39%. However, neither product was effective when the films were applied to the internal surface of windows. Hence, it is imperative that installers apply these products to exterior surfaces of windows to render their protective benefits and reduce the risk of daytime window collision.

Scalability Improvement of IEEE 802.11ah IoT Networks

In this paper, we propose a non-orthogonal multiple access (NOMA) based grouping method for IEEE 802.11ah, a promising platform for the internet of things (IoT). The grouping method improves the scalability of IoT networks, by reducing collisions in the access points (APs). The proposed method puts those IoT devices (IoT-Ds) whose channel gains are far enough from each other, i.e., who satisfy NOMA constraints, in the same group. Therefore, using successive interference cancellation (SIC), the AP is able to decode the simultaneous signal transmissions from IoT-Ds in a group. To assign IoT-Ds into groups and determine their transmission power, we formulate a total throughput maximization problem as a joint optimal grouping and power allocation problem, which is a non-convex mixed-integer programming problem. We convert it to a convex problem using quadratic fractional programming, and then we solve it using augmented Lagrange multiplier (ALM) method. Moreover, to reduce the complexity of the solution, we propose a fast grouping method to allocate power to each group in parallel. Simulation results show that the proposed methods have outstanding performance compared to conventional association identifier (AID)-based grouping method; besides, scalability of the network in terms of throughput, power consumption and channel utilization improves dramatically because of the collision reduction of IoT-Ds, which is achieved by deploying NOMA and SIC. Furthermore, the fast grouping method decreases the computational complexity greatly at the expense of a small reduction in network performance.

Ungulate use of an at-grade fauna passage and roadside animal detection system: A pilot study from Southern Sweden

Wildlife-vehicle collisions (WVC) cost millions of euros each year in loss of life and damages. Wildlife crossing structures and fencing are commonly implemented mitigation strategies to reduce WVC and increase landscape connectivity for wildlife. Typically, crossing structures are over- or under-pass structures that allow animals to safely cross the road, while separating them from the road and traffic. An alternative strategy could be an at-grade fauna passage coupled with a Roadside Animal Detection System (RADS). At-grade fauna passages are designated locations where a gap in fencing allows animals to cross over the road, while RADS alert drivers of animals at the upcoming passage, so that they can adjust their driving behaviour accordingly and avoid collisions. In this pilot study, we investigated the use of one at-grade fauna passage by roe deer (Capreolus capreolus), red deer (Cervus elaphus) and wild boar (Sus scrofa) in southern Sweden, and compared changes in the number of WVCs before, during and after the construction of the passage. We collected a total of 326 wildlife crossings from 722 individuals over 1 year of monitoring (24 January 2020–24 January 2021). We found that crossing events tended to be dominated by the time animals spent in the roadside verge from which they approached the at-grade fauna passage, particularly for roe deer that spent a lot of time browsing in the roadside verge during dusk. We also found that animals spent longer in the passage if vehicles were present. In our 1 year of surveys, we only recorded three accidents, and when comparing the annual collision statistics before, during, and after construction of the at-grade fauna passage, we demonstrated an overall reduction in collisions by 66%. While our pilot only evaluates a single site, it does provide promising preliminary results that suggest that at-grade fauna passages can help in efforts to reduce collisions, while maintaining connectivity over medium-sized roads for large ungulates.

An On-Site-Based Opportunistic Routing Protocol for Scalable and Energy-Efficient Underwater Acoustic Sensor Networks

With the advancements in wireless sensor networks and the Internet of Underwater Things (IoUT), underwater acoustic sensor networks (UASNs) have attracted much attention, which has also been widely used in marine engineering exploration and disaster prevention. However, UASNs still face many challenges, including high propagation latency, limited bandwidth, high energy consumption, and unreliable transmission, influencing the good quality of service (QoS). In this paper, we propose a routing protocol based on the on-site architecture (SROA) for UASNs to improve network scalability and energy efficiency. The on-site architecture adopted by SROA is different from most architectures in that the data center is deployed underwater, which makes the sink nodes closer to the data source. A clustering method is introduced in SROA, which makes the network adapt to the changes in the network scale and avoid single-point failure. Moreover, the Q-learning algorithm is applied to seek optimal routing policies, in which the characteristics of underwater acoustic communication such as residual energy, end-to-end delay, and link quality are considered jointly when constructing the reward function. Furthermore, the reduction of packet retransmissions and collisions is advocated using a waiting mechanism developed from opportunistic routing (OR). The SROA realizes opportunistic routing to choose candidate nodes and coordinate packet forwarding among candidate nodes. The scalability of the proposed routing protocols is also analyzed by varying the network size and transmission range. According to the evaluation results, with the network scale ranging from 100 to 500, the SROA outperforms the existing routing protocols, extensively decreasing energy consumption and end-to-end delay.

Investigating the impact of a 20 miles per hour speed limit intervention on road traffic collisions, casualties, speed and volume in Belfast, UK: 3 year follow-up outcomes of a natural experiment

BackgroundEvidence regarding the effectiveness of 20 miles per hour (mph) speed limit interventions is limited, and rarely have long-term outcomes been assessed. We investigate the effect of a 20 mph...

Using actor maps and AcciMaps for road safety investigations: Development of taxonomies and meta-analyses

The number of road collisions have plateaued over the past decade, both in the UK and worldwide. One problem is that most road safety investigations focus on the immediate, sharp-end factors rather than delving into the deeper, blunt-end, systems factors. It is argued that the contributions of both of these types of factors need to be understood before further reductions in road collisions can be made. The study reported in this paper developed taxonomies for Actor Maps and AcciMaps from 37 road collision investigation reports undertaken in the UK. The meta-analysis of the Actor Maps showed that relatively few categories of actors are associated with the majority of collisions (i.e., 35/256). Similarly, the meta-analysis of the AcciMaps showed that all of the 1656 actions, events and decisions (or lack of) could be placed into 19 categories. Across the eight AcciMap levels there were 11 categories that appeared most frequently. Both of these taxonomies together with the meta-analysis enabled a summary of the analysis and derivation of interventions at a national level. The study also points toward a common contributory (and protective) network for road collisions. The meta-analysis showed that the ‘sharp-end’ accounted for approximately 40% of the factors (those that are normally investigated in collisions) whilst the blunt-end accounted for approximately 60% of the factors. These blunt-end factors are often not addressed in traditional police-led collision investigations, as these investigations typically focus on establishing individual criminal culpability. Any future road collision investigations which aim to identify no blame safety learning should seek to understand blunt end factors as they create the pre-conditions for incidents to occur.

A Collision Reduction Adaptive Data Rate Algorithm Based on the FSVM for a Low-Cost LoRa Gateway

LoRa (Long Range), a wireless communication technology for low power wide area networks (LPWANs), enables a wide range of IoT applications and inter-device communication, due to its openness and flexible network deployment. In the actual deployment and operation of LoRa networks, the static link transmission scheme does not make full use of the channel resources in the time-varying channel environment, resulting in a poor network performance. In this paper, we propose a more effective adaptive data rate (ADR) algorithm for low-cost gateways, we firstly analyze the impact of the different hardware parameters (RSSI, SNR) on the link quality and classify the link quality using the fuzzy support vector machine (FSVM). Secondly, we establish an end device (ED) throughput model and energy consumption model and design different adaptive rate algorithms, according to the different link quality considering both the link-level performance and the MAC layer performance. The proposed algorithm uses machine learning to classify the link quality, which can accurately classify the link quality using a small amount of data, compared to other adaptive rate algorithms, and the link parameter adaptation algorithm can maximize the throughput while ensuring the link stability, by considering the link-level performance and the MAC layer performance, compared to other algorithms. The results show that it outperforms the standard LoRaWAN ADR algorithm in both the single ED and the multi ED scenarios, in terms of the packets reception rate (PRR) and the network throughput. Compared to the LoRaWAN ADR in 32 multi-ED scenarios, the proposed algorithm improves the throughput by 34.12% and packets the reception rate by 26%, significantly improving the network throughput and the packets reception rate.

Evaluating the Effectiveness of Onboard Video Feedback Systems on Reducing Transit Collisions and Injuries

In the mid-2000s, public transit agencies began testing onboard video feedback systems on buses, which capture short video clips when triggered by an unusual event such as hard braking, a sharp turn, or impact with an object. The objective of this study was to determine whether the systems have enhanced passenger safety by reducing the frequency and severity of collisions and injuries and to identify lessons learned from the implementation of such systems. The study concludes that the systems appear to have a positive impact on transit safety achieved through a reduction in collisions and injuries and the risky driving behaviors that contribute to them. The systems provide transit mangers with a wealth of information about their employees’ driving habits that was not previously available. Transit agencies should consider investing in such systems as one component of an overall safety and training program.

The effectiveness of built environment interventions embedded in road safety policies in urban municipalities in Canada: An environmental scan and scoping review

IntroductionInjuries and deaths from motor vehicle collisions are a significant public health issue. As public health researchers and practitioners, we must support the work of municipalities by advocating for effective interventions to reduce this burden. This requires an evidence-based approach; however, many interventions embedded in existing road safety policies in Canada are not supported by evidence. The objective of this work was to review the built environment (BE) interventions in road safety policies in five, urban municipalities in Canada and summarize the peer-reviewed literature to support them. MethodsData were retrieved through an environmental scan of road safety policies across five Canadian urban municipalities, supplemented by a scoping review of articles indexed in MEDLINE and a grey literature search. Inclusion criteria were: 1) BE interventions, 2) collision or collision pathway outcomes (e.g., vehicle speed, vehicle volume), 3) evaluative study designs, and 4) studies published less than 20 years ago (i.e., 1999–2019). We critically appraised the included studies using the TREND checklist. Data were extracted and summarized, grouped by intervention type. ResultsThe environmental scan yielded 42 BE interventions within the existing road safety policies across CHASE regions. The scoping review found a total of 124 studies; the final sample included 45 studies with 29 interventions. The median TREND score [interquartile range (IQR)] was 16 (15, 17) out of 22. Published scientific evidence was not found for 13interventions. ConclusionsA low proportion of included studies specific to the existing road safety policies in urban areas in Canada demonstrated a reduction in collisions. Further, significant variability in the level of effectiveness across interventions exists. Information specific to the effectiveness of interventions should be an integral part of the decision making process for BE change; however, more work is needed to better understand critical decision making factors. Mesh and keywordscollisions, traffic; injuries and wounds; policy; review, scoping.

A Packet Collision Reduction Based on Reselection for LTE V2X Mode 4

Vehicle to Everything (V2X) is a technology that includes communication between the vehicles and everything such as Vehicle to Vehicle (V2V), Vehicle to Infrastructure (V2I), and Vehicle to Pedestrian (V2P). Long Term Evolution (LTE) V2X based on LTE supports a sidelink communication in which User Equipment (UE) communicates with each other. In Mode 4 of the sidelink communication, the UE autonomously selects a radio resource that is not expected to be used by other UEs based on sensing information. However, a resource can be selected by simultaneous UEs and packet collisions occur because of the periodic resource reselection. In this paper, we propose two resource selection methods for the reselection using information originally included in the control information. Through computer simulations, we show that the proposed methods can improve the packet reception rate without requiring restrictions such as additional information. The main strength of this method is that it effectively utilizes the information contained in Resource Reservation Interval (RRI), which is used in the Semi-Persistent Scheduling wireless resource allocation algorithm. In this research, the value of RRI, which has been used in standards, is utilized to improve performance while maintaining compatibility. Since our method is designed under conditions that maintain compatibility with existing standards, it may or may not have a significant effect, but it does not degrade performance.

A Packet Collision Reduction Based on Reselection for LTE V2X Mode 4

A Packet Collision Reduction Based on Reselection for LTE V2X Mode 4

Impact of Wildlife Crossing Structures on Wildlife–Vehicle Collisions

This paper examines whether wildlife crossing structures reduce the number of wildlife–vehicle collisions. Using Washington state crash data from 2011 to 2020, I employed a difference-in-differences methodology at the year level on each of 13 observed wildlife crossing structures in Washington. The treatment area consisted of wildlife–vehicle collisions within 10 mi of a wildlife crossing structure, and the control area included wildlife–vehicle collisions that were 60 to 70 mi from the same wildlife crossing structure. I found evidence that wildlife crossing structures resulted in one to three fewer wildlife–vehicle collisions on average per mile per year. The marginal treatment effect also held within a 5-mi treatment area, a 15-mi treatment area, and when controlling for the presence of other structures within the baseline of a 10-mi treatment area. However, the collision reductions were more consistent among wildlife bridges than culverts, suggesting that not all wildlife crossing structures have the same effect in reducing accidents involving wildlife. Using a back-of-the-envelope approach, each wildlife crossing structure yielded annual benefits of $235,000 to 443,000 in 2021 U.S. dollars.

To determine if changing to white light street lamps improves road safety: A multilevel longitudinal analysis of road traffic collisions during the relighting of Leeds, a UK city

Large-scale installation of broad-spectrum (white) road lighting has been claimed to bring about a substantial reduction in road traffic collisions (RTCs). This confirmatory study estimates the effect on personal injury RTCs of a relighting programme that installed nearly 80,000 new white lamps, between the years 2005 and 2013, throughout the large UK city of Leeds. Time series of weekly RTC personal injury counts in 107 areas, within the city over nearly 9 years when its road lighting was almost completely relit, were analysed, using multilevel modelling. The background change in each area when and where no lighting was being changed was separated from that associated with when and where new replacement white lamps were installed by including a polynomial for the underlying time-trend. The key interest is how the installation of the new lamps affects the ratio of the rate of collisions occurring in darkness to those occurring in daylight. The measure sought is given by the daylight adjusted darkness collision rate ratio (CRR) for the specified amount of relighting, that is the factor by which the daylight adjusted collision rate changes by the specified change in lighting. The daylight adjusted darkness collision rate ratio (CRR) has a point estimate of 0.990 and a 95% confidence interval, CI (0.971, 1.010) for 100 replaced lamps; representing a range between a 3% reduction in the collision rate to a 1% increase. Using the series truncated at the end of 2011 that seems more trustworthy, gives a revised point estimate of 0.993 and a CI (0.971, 1.015). Both CIs include one, therefore no effect on road safety was detected. The CIs for any other number of lamps installed will also include one. Typically, the plausible range of road safety impact brought by the new white lamps for a typical area with 700 lamps, roughly spans 20% reduction to a 10% increase for the daylight adjusted darkness collision rate. No convincing evidence was found for an improvement (or detriment) in road safety by relighting with white lamps, despite the extensive, city-wide installation efforts and associated costs.

Operational and safety impacts of integrated variable speed limit with dynamic hard shoulder running

The combination of various Intelligent Transportation System (ITS) strategies generally has manifold effects, much greater than when strategies are implemented individually. This research introduces a novel dynamic control strategy, which includes the dynamic use of a Model Predictive Control (MPC) based Variable Speed Limit (VSL) integrated with the dynamic use of Hard Shoulder Running (HSR). Both VSL and HSR are proactively triggered to allow for necessary control measures to be taken to delay and possibly avoid the formation of a bottleneck. For traffic prediction, a modified METANET model is developed which takes into consideration the complex nature of driver’s behavior along with driver’s compliance, capacity drop and posted speed limits. The modified METANET model is shown to be more efficient than conventional macroscopic prediction models in detecting traffic congestions. This MPC based strategy was tested on a section of Deerfoot Trail, Calgary, Alberta using an exclusively developed integrated VISSIM-COM-MATLAB interface. The results from this study suggested that the integrated VSL and HSR control strategy results in a 21.09% increase in average speed and 33.44%. in vehicle-throughput. Furthermore, there was a noticeable reduction in the average travel time by 39.98% and in the total number of stops, by 32.43%. Importantly, the safety analysis performed using Surrogate Safety Assessment Model (SSAM) revealed a notable reduction in collisions, by 29.73%.

An improved RFID anti-collision protocol (IMRAP) with low energy consumption and high throughput

The advancement of RFID (Radio Frequency Identification) has facilitated its widespread incorporation and caused an increase in the deployment of these solutions in a variety of contexts and constraints. These constraints are generally due to the quantity and the mobility of tags and readers utilized, both of which have an impact on the RFID system's efficiency by causing tag collisions. Whereas numerous solutions to the problem of tag collisions have been presented, few of them have been concerned with reducing collisions, energy consumed, and maximizing throughput at the same time. This article proposes an approach to estimate tags for attaining these objectives based on an x factor, which functions as a reward or a penalty depending on the performance of the frame. When compared to previous collision reduction protocols, simulations reveal that our solution achieves the highest performance in terms of throughput, collisions, and energy consumed.

REDUCING ENERGY CONSUMPTION IN IOT BY A ROUTING WHALE OPTIMIZATION ALGORITHM

The Internet of Things is a new concept in the world of information and communication technology, in which for each being (whether it be a human, an animal or an object), the possibility of sending and receiving data through communication networks such as the Internet or Intranet is provided. Wireless sensors have limited energy resources due to their use of batteries in supplying energy, and since battery replacement in these sensors is not usually feasible, the longevity of wireless sensor networks is limited. Therefore, reducing the energy consumption of the used sensors in IoT networks to increase the network lifetime is one of the crucial challenges and parameters in such networks. In this paper, a routing protocol has been proposed and stimulated which is based on the function of the whale optimization algorithm. Clustering is performed through a routing method which is based on energy level, collision reduction, distance between cluster head node and destination, and neighbor energy. Furthermore, the selection of the cluster head node is performed based on the maximum remaining energy, the least distance with other clusters, and energy consumption, where energy consumption for reaching the base station is minimized. By de-creasing the level of cluster head energy from the specified threshold value from among the nodes in the same cluster, a node with an energy level above the threshold would be selected as the new cluster head. Moreover, four conditions (i.e. the shortest route, the leading route, the least distance to the source node, and destination node) are applied for routing. The proposed method was compared to LEACH, EEUC, EECRP, BEAR and CCR algorithms, and the results indicated the superiority of the proposed method to other methods in terms of the number of dead nodes.

Collision Reduction Walking for Lower Limb Exoskeletons

Lower limb exoskeletons have received considerable interest in strength augmentation, rehabilitation, and walking assistance scenarios. For walking assistance, repetitive and excessive foot-ground impact makes the patient uncomfortable and even leads to secondary damage. In this paper, variable stiffness ankles are used for collision reduction walking, based on which the Step Length-depended Variable Stiffness Planner (SLVSP) is proposed for lower limb exoskeletons. In the SLVSP, ankle stiffness and step length are optimized to reduce the Collision Loss Of Transport (CLOT). In addition, the mechanical energy-based human intention estimator for continuous walking by the SLVSP is proposed. A dynamics simulation verifies the method’s performance, and the results show that the proposed approach is effective.

Bird protection treatments reduce bird-window collision risk at low-rise buildings within a Pacific coastal protected area.

BackgroundIn North America, up to one billion birds are estimated to die annually due to collisions with glass. The transparent and reflective properties of glass present the illusion of a clear flight passage or continuous habitat. Approaches to reducing collision risk involve installing visual cues on glass that enable birds to perceive glass as a solid hazard at a sufficient distance to avoid it.MethodsWe monitored for bird-window collisions between 2013 and 2018 to measure response to bird protection window treatments at two low-rise buildings at the Alaksen National Wildlife Area in Delta, British Columbia, Canada. After 2 years of collision monitoring in an untreated state, we retrofitted one building with Feather Friendly® circular adhesive markers applied in a grid pattern across all windows, enabling a field-based assessment of the relative reduction in collisions in the 2 years of monitoring following treatment. An adjacent building that had been constructed with a bird protective UV-treated glass called ORNILUX® Mikado, was monitored throughout the two study periods. Carcass persistence trials were conducted to evaluate the likelihood that carcasses were missed due to carcass removal between scheduled searches.Results and ConclusionsAfter accounting for differences in area of glass between the two buildings, year, and observer effects, our best-fit model for explaining collision risk included the building’s treatment group, when compared to models that included building and season only. We found that the Feather Friendly® markers reduced collision risk at the retrofitted building by 95%. Collision incidence was also lower at the two monitored façades of the building with ORNILUX® glass compared to the building with untreated glass. Although more research is needed on the effectiveness of bird-protection products across a range of conditions, our results highlight the benefit of these products for reducing avian mortality due to collisions with glass.

Does predation by wolves reduce collisions between ungulates and vehicles in France?

ABSTRACT The recolonization of French forests by wolves is met with mixed feelings. While the spotlight is on predation of wolves on livestock, the potential benefit of the return of wolves has attracted less attention. Previous research has failed to assess the economic value of these benefits and focused only on the cost of predation. Our study proposes a modeling exercise to evaluate one of the services provided by wolves, namely, the reduction of collisions between wildlife and vehicles in France. We estimated that in 2018 the consumption of roe deer and wild boar by wolves saved between 2.4–7.8 million euros by preventing casualties and damage to property in road collisions. Offsetting this benefit with the costs of managing livestock predation could move the debate away from a simple clash between herders and environmentalists toward a more systemic approach and thus improve coexistence between wolves and humans.