{"title":"Distracting or informative? Examining signage for cyclists using eye-tracking","authors":"Ole Aasvik, A. Fyhri","doi":"10.55329/wxcy5694","DOIUrl":"https://doi.org/10.55329/wxcy5694","url":null,"abstract":"There is great political motivation to improve conditions for cyclists to help solving the transport needs of the future. We used eye-tracking to collect data and analysed it using a novel machine learning approach. 40 cyclists in total were tasked with navigating a set route through the Oslo city centre. One group before the new infrastructure was in place and one group after. The analysis focused on developing a method that could be used to investigate how a new signage strategy impacted cyclists in Oslo. Improving signage could create safer traffic conditions for cyclists, while avoiding adding distracting elements. The algorithms developed were able to detect and categorize a variety of important objects. The signage system itself seemed to result in some route change among cyclists, but not all followed the suggested route. Qualitative analyses suggests that those who deviated cycled faster and looked less at signs, than those who chose the suggested route. The paper discusses strengths and weaknesses involved in this approach. While useful, one should be careful to conclude that gaze behaviour reflects the true inner consciousness of cyclists.","PeriodicalId":204673,"journal":{"name":"Traffic Safety Research","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126159387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Descriptive analysis of reports on autonomous vehicle collisions in California: January 2021–June 2022","authors":"P. Pokorný, A. Høye","doi":"10.55329/xydm4000","DOIUrl":"https://doi.org/10.55329/xydm4000","url":null,"abstract":"The characteristics of autonomous vehicles’ collisions from 2021 and the first half of 2022 in California confirm trends reported in previous years. Driving in autonomous mode was associated with fewer instances in which the AV was deemed to be at fault in a collision. Most collisions in autonomous mode were rear-end collisions at intersections. Single vehicle collisions occurred mostly in manual mode. Collisions with vulnerable road users occurred mostly while the autonomous vehicle was in manual mode, often right after disengagement from autonomous mode. In collisions with other vehicles that occurred after disengagement, the other vehicles were frequently deemed to be at fault. Compared to 2021, the collision reports from the first half of 2022 indicate higher shares of collisions in autonomous mode, rear-end collisions, and collisions with vulnerable road users.","PeriodicalId":204673,"journal":{"name":"Traffic Safety Research","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122298224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Identification of evasive manoeuvres in traffic interactions and conflicts","authors":"C. Johnsson, A. Laureshyn","doi":"10.55329/erqd8683","DOIUrl":"https://doi.org/10.55329/erqd8683","url":null,"abstract":"The study presents a simple and easy to implement method for detection of the evasive action start in traffic interactions. The method is based on comparison of the studied trajectory with a reference set of ‘unhindered’ trajectories, interpreting the start of evasive action as the moment when no more similarities can be found. The suggested algorithm performs well for primary interactions when road users arrive in an unhindered state. It fails, however, in case of secondary interactions. Explorative application of the method on a large dataset of normal and conflict traffic situations concludes that traffic conflicts occur more frequently in secondary interactions, presumably due to higher cognitive load on the involved road users. Despite the limitations, the method can be used both for the safety studies based on traffic conflicts and for more general quantification and visualisation of the road user behaviour.","PeriodicalId":204673,"journal":{"name":"Traffic Safety Research","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123712899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The role of values in road safety culture: Examining the relationship between valuation of freedom to take risk and accident risk among motorcycle riders and car drivers","authors":"Tor-Olav Nævestad, A. Laiou, G. Yannis","doi":"10.55329/ggnj7534","DOIUrl":"https://doi.org/10.55329/ggnj7534","url":null,"abstract":"Focus on paternalistic values versus individual freedom is a fundamental theme, which defines the status of road safety in different settings. The present study examines the role of values related to freedom to take risk in traffic in road safety culture based on survey data from car drivers (n = 882) and motorcycle riders (n = 330) from two countries with distinctly different road safety records: Norway, which had the lowest road mortality rate in Europe with 20 road deaths per million inhabitants in 2017, and Greece, which had 69 road deaths per million inhabitants, which was well above the EU average of 50. Contrary to our first hypothesis, we do not find a statistically significant higher valuation of freedom to take risk in traffic among Greek drivers and riders than among drivers and riders from Norway. In line with our second hypothesis, we find that motorcycle riders in both countries value freedom to take risk in traffic significantly higher than car drivers in their country. Regression analyses indicate a relationship between higher valuation of freedom to take risk in traffic and risky rider behaviours, which are related to accident involvement. Our results indicate that values focusing on freedom to take risk have an important role in road safety culture, presumably legitimizing and motivating risky driving/riding. This is in line with previous research, where riders cite freedom as the main enjoyment factor for riding. Previous studies find six times higher accident risk among riders than drivers, which is explained partly by pointing to risky rider behaviours.","PeriodicalId":204673,"journal":{"name":"Traffic Safety Research","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115807120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Which is the more important for road safety—road design or driver behavioural adaptation?","authors":"R. Elvik","doi":"10.55329/pvir7839","DOIUrl":"https://doi.org/10.55329/pvir7839","url":null,"abstract":"Studies consistently show that sharp horizontal curves increase accident rate. One would therefore expect roads with many sharp curves to have a higher accident rate than roads with few sharp curves. This is not the case. The differences in road safety between roads with different profiles of horizontal road alignment are quite small. There are even studies suggesting that areas having roads with many curves have a lower number of accidents than otherwise identical areas with less curvy roads. The question arises: How can it be true both that sharp curves increase accident rate and that areas with roads with many sharp curves do not have a higher accident rate than areas with less demanding alignment? The answer is likely to be found in behavioural adaptation among drivers. The accident rates both in curves and on straight sections are strongly influenced by how drivers adapt behaviour to the number of curves per kilometre of road. This paper shows how behavioural adaptation can be quantified by means of the ‘human feedback parameter’ proposed by Evans. This parameter takes a value of -1 if drivers adapt behaviour so as to completely eliminate a risk factor. Values close to -0.7 for horizontal curves were estimated on the basis of micro-level studies. Thus behavioural adaptation reduces the increase in risk to about 30% of what it would have been without behavioural adaptation. In addition, a high frequency of curves leads to lower speed on the straight sections between curves.","PeriodicalId":204673,"journal":{"name":"Traffic Safety Research","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122662071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tim De Ceunynck, Brecht Pelssers, T. Bjørnskau, Ole Aasvik, A. Fyhri, A. Laureshyn, C. Johnsson, M. Hagenzieker, H. Martensen
{"title":"Interact or counteract? Behavioural observation of interactions between vulnerable road users and autonomous shuttles in Oslo, Norway","authors":"Tim De Ceunynck, Brecht Pelssers, T. Bjørnskau, Ole Aasvik, A. Fyhri, A. Laureshyn, C. Johnsson, M. Hagenzieker, H. Martensen","doi":"10.55329/fbhr3456","DOIUrl":"https://doi.org/10.55329/fbhr3456","url":null,"abstract":"The current paper presents the results of behavioural observations in a field experiment with automated shuttles in Oslo, Norway. Video observations were conducted at five fixed locations along a challenging 1.2 km automated shuttle line with varying traffic conditions. Observed interactions between vulnerable road users and automated shuttles were coded using a predefined codebook, which allowed a structured quantitative analysis. The paper identified several potentially risky types of situations in which the automated shuttles did not always behave according to the traffic rules. Generally, the automated shuttles failed to give way to pedestrians at pedestrian crossings in 26%–50% of the interactions. Right-turning shuttles failed to yield to cyclists going straight in 38% of the interactions at observation Site 1 (the only location where the automated shuttle takes a right turn). In majority of same direction interactions between cyclists and automated shuttles, the interactions resulted in the cyclist overtaking the automated shuttle, usually on the left-hand side. Generally, the paper found little evidence of road users trying to bully or otherwise take advantage of the defensive driving style of the automated shuttles and identified only a limited number of interactions in which a vulnerable road user behaved ignorant or aggressive towards the automated shuttles. In addition, the paper found very little indication of temporal effects that suggest changes in the interaction patterns over time.","PeriodicalId":204673,"journal":{"name":"Traffic Safety Research","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128392056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Do we know why the number of traffic fatalities is declining? If not, can we find out?","authors":"R. Elvik, A. Høye","doi":"10.55329/oyhu8693","DOIUrl":"https://doi.org/10.55329/oyhu8693","url":null,"abstract":"The number of traffic fatalities has declined by 80-90 % from the all-time peak number in many highly motorized countries. It would be of great interest to identify factors that explain this decline. Unfortunately, this is difficult, and an ideal method does not exist. This paper discusses some less-than-ideal methods. Multivariate statistical analyses are unlikely to be informative because they are likely to be affected by both multicollinearity and omitted variable bias. This implies that they will always include both too many and too few predictor variables, a problem that is impossible to solve. Historical reconstruction is another possible method. It explains fatality reductions over time by known factors that are related to fatalities and for which sufficient information about their presence or uptake is available. Studies based on historical reconstructions show consistently that safer road user behavior is a major contributor to reducing fatalities, followed by infrastructure and vehicle related safety measures. However, there is no way of establishing causality. The relative importance of different types of factors is highly dependent on the amount of information available. In a strict sense, there is therefore no prospect of providing a scientific explanation of the decline in traffic fatalities. In a less strict sense, historical reconstructions still may give an impression of relative contributions of some known factors. For example, the most recent Norwegian study identified factors that may explain more than half of the reduction of road traffic fatalities after 2000.","PeriodicalId":204673,"journal":{"name":"Traffic Safety Research","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115519955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Safe speeds: fatality and injury risks of pedestrians, cyclists, motorcyclists, and car drivers impacting the front of another passenger car as a function of closing speed and age","authors":"N. Lubbe, Yi Wu, H. Jeppsson","doi":"10.55329/vfma7555","DOIUrl":"https://doi.org/10.55329/vfma7555","url":null,"abstract":"As crash speed increases, so does the probability of injury. The vulnerability of different road users varies greatly, in part due to differences in their protective equipment. Therefore, for the same speed, their injury probabilities are different. The objective of this study is to define injury risk curves, mathematical relations between closing speed (the relative speed between two crash partners) and injury outcome, for different road users. These risk curves can be used to rank road user vulnerability and define safe speeds, i.e. speeds not exceeding tolerable injury probabilities. Crashes involving pedestrians, cyclists, motorcyclists, and car drivers impacting the front of another passenger car (i.e. frontal impacts from the other car’s perspective) were extracted from the German in-depth accident study (GIDAS). The injuries were modelled as a function of closing speed and road user age using a weighted binary logistic regression. In accordance with the Abbreviated Injury Scale 2015 revision, three injury severities were modelled: at-least-moderate injury severities, at-least-serious injury severities, and fatal injuries. The constructed risk curves predicted injury outcomes with an average Area under the Curve ranging from 0.66 to 0.94 in cross-validation. A 10% risk of sustaining at-least-serious injuries corresponds to a closing speed of 29 km/h for pedestrians, 44 km/h for cyclists, 48 km/h for motorcyclists, and 112 km/h for car drivers. If a 10% risk of serious injury is acceptable, the closing speeds can be translated into safe speed limits of 25 km/h for cars with pedestrian encounters; 20 to 25 km/h for cyclists, motorcyclists, and cars when they encounter each other; and 55 km/h for cars in head-on impacts. These safe speeds align with current speed limits of 20 to 30 km/h in urban centers but bring into question the current practices of much higher speed limits on rural roads shared by bicycles, motorcycles, and cars. However, safe speed limits could be increased (maintaining a 10% serious injury risk) if road users have more protective equipment and Automated Emergency Braking reliably reduces impact speeds in all crash types.","PeriodicalId":204673,"journal":{"name":"Traffic Safety Research","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114043183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"GIS techniques to analyze factors associated with crash occurrence","authors":"Shraddha Sagar, N. Stamatiadis","doi":"10.55329/wmfk3422","DOIUrl":"https://doi.org/10.55329/wmfk3422","url":null,"abstract":"Fatality rates in Kentucky have been higher than the national average for the past decade. Prior research postulated that the region’s unique socioeconomic conditions could provide a compelling explanation of the higher cash rates of the southeast in the US. This study examines the relationship between safety and socioeconomic characteristics using an extensive spatial analysis of crashes in Kentucky. Quasi-induced exposure technique was utilized to determine the crash propensity of different driver groups. Through a series of GIS techniques and spatial analysis, the relative accident involvement ratios were calculated for each group of drivers. The findings of the study concur with the previous findings between driving behavior and demographic factors such as age and gender. The study also attempted to explain the regional disparities in crash occurrence across the state in terms of economic status. The study concluded that the drivers residing in the Appalachian regions have a higher propensity to cause a crash, regardless of the age and gender of the driver. The findings of the study can be used to identify high risk counties for the Safety Circuit Rider (SCR) program in Kentucky.","PeriodicalId":204673,"journal":{"name":"Traffic Safety Research","volume":"2016 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127464871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Rollator related pedestrian single accidents and collision events in Sweden","authors":"Anna Carlsson, J. Lundälv","doi":"10.55329/cysb9519","DOIUrl":"https://doi.org/10.55329/cysb9519","url":null,"abstract":"Rollators (four-wheel walkers in USA; zimmer frames in UK) are commonly used as mobility aids for the elderly and people with a variety of disabilities. Pedestrian rollator users are a sub-group of Vulnerable Road Users (VRUs), although this group is rarely recognised in traffic safety contexts. The aim of this study is to extract and analyse rollator related pedestrian accident and injury data in Sweden. The results will provide valuable insight into the risks and obstacles rollator users are exposed to in the traffic environment and may in the long term contribute to improving the mobility of this group. The current study is based on data from 2,020 accidents involving 2,305 persons extracted from the Swedish Traffic Accident Data Acquisition (STRADA) database. For consistency reasons, a subset of data (N = 745) was analysed in order to investigate the development of accidents over a period of 10 years. Thereafter, each accident in the whole data set was registered as either single or collision. The results show that the number of rollator accidents in Sweden increased by approximately 80% during 2007–2016. Females dominate the injury statistics of single accidents, collisions, as well as fatal outcome, which may be due to exposure and/or differences in physical characteristics. Single accidents are much more common than collisions (n=1,668 and n=352, respectively) and the injury consequences are at least as serious. Data from the present study have revealed that the frequency of minor injuries (ISS 1–3) is 4.3 times, moderate (ISS 4–8) 6.0 times and serious injuries (ISS 9–15) 8.9 times higher in single accidents than in collisions. Fatal injuries are, however, more common in collision events (33 in comparison to 8). The vast majority of single accidents (99%) was due to falls. Many of the single accidents (29%) were caused by ground level differences (typically a curb) or due to surface conditions (19%). Collisions involved cars, trucks or buses in 91% of cases, occurring predominantly in car parks (31%) and on (zebra) crossings (30%). In 54% of cases the vehicles reversed into the rollator. Abbreviated Injury Scale (AIS) 3+ injuries were dominated by head (36%) and torso (33%) injuries in collision events, and hip fractures (71%) in single accidents. The present study shows that further research into rollator user related accidents, both single accidents and collision events, is required. In order to introduce appropriate measures, future work should follow up on accident and injury developments and further improve the quality of mobility aid related accident data in general. Improved stability and design, proper training programmes, effective maintenance services, development of a supporting infrastructure would contribute to increased safety for rollator users.\u0000 ","PeriodicalId":204673,"journal":{"name":"Traffic Safety Research","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128587899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}