Please stop now,automated vehicle! – Passengers aim to avoid risk experiences in interactions with a crossing vulnerable road user at an urban junction

The success of highly automated vehicles (HAVs; SAE Level 4) will depend to a large extent on how well they are accepted by their future passengers. This is especially true for the interaction of these vehicles with other human road users in mixed traffic. In future urban traffic, passengers of HAVs will observe from a passive position how the automated system resolves space-sharing conflicts with crossing vulnerable road users (VRUs; e.g., pedestrians and cyclists) at junctions. For one such crossing-paths conflict, we investigated when passengers would want the HAV to start braking and how much perceived risk passengers accept in the interaction of their vehicle with VRUs. To this end, we conducted 1) an online video study (N = 118), 2) a driving simulator study (N = 28), and 3) a human&vehicle-in-the-loop (Hu&ViL) study at a test site (N = 10). We varied the speed of the HAV (30 km/h vs. 50 km/h), the type (cyclist vs. pedestrian), and crossing direction of the VRU (left vs. right). During the approach to the junction, passengers' task was to trigger the HAV's braking maneuver, in a first trial at the point they considered ideal and in a second trial at the last point they still considered safe enough to decelerate and come to a stop at the stop line. For each braking maneuver, we analyzed the HAV’s distance and time-to-arrival (TTA) to the VRU at braking onset, as well as passengers’ perceived risk in the VRU interaction. The results showed that most passengers preferred harmless interactions with VRUs (at the ideal braking onset time), and accepted unpleasant, but not dangerous interactions at most (at the last acceptable braking onset time). Methodologically, the results were very similar in the three different environments (online, driving simulator, real vehicle). These results clearly show that, in addition to the technical considerations of safe automated driving, passengers’ perception and evaluation of HAV driving behavior should also be taken into account to achieve a satisfying level of acceptance of these vehicles.     

Self-reported Attitude Towards Speeding and Its Possible Consequences in Five Different Road Contexts

Driving above the permitted speed limit is a common violation on the roads of Great Britain. Moreover, speeding is associated with negative consequences in the form of damage, injury and fatal road traffic accidents. The aim of this study was to assess, by means of self-report, the prevalence of this social problem across five different contexts: a residential road, a busy shopping street, a dual carriageway, a winding country road, and a motorway. The extent to which speeding was perceived to be associated with negative consequences was also assessed. Results suggest that most drivers make judgements about the type of road on which they are driving and the degree of speeding that is acceptable, and that their intentions to speed vary accordingly. Some drivers reported a consistent intention to speed, however, and these people were characterized by greater general deviance on the road (e.g. high violation score), rather than by a stronger tendency to underestimate the negative consequences. In general, however, younger people and those with less regard for negative consequences reported stronger intentions to speed. These results are discussed with reference to strategies for addressing the problem of speeding. © 1997 John Wiley & Sons, Ltd.     

驾驶员选择性注意过程中的规则图式启动效应

本研究将驾驶无意视盲范式与交通违规事件识别任务相结合, 通过两个实验分别探究任务性质(有提示、无提示)和规则图式训练(训练、未训练)对驾驶员识别交通信号和违规事件的影响。结果发现, 交通规则提示能够提高有经验的驾驶员识别交通信号的正确率(实验1); 对于新手驾驶员, 则需要结合规则图式训练才能起到相同效果(实验2)。研究表明驾驶员选择性注意过程中存在规则图式启动效应, 图式训练能够弥补新手驾驶员经验的不足。     

Public health consequences of road traffic injuries – Estimation of seriously injured persons based on risk for permanent medical impairment

Despite the fact, that Sweden has one of the safest traffic environments in the world, a large number of people are still injured in road traffic accidents in Sweden. The core concept of the Vision Zero that was adopted by the Swedish parliament in 1997 is to decrease the number of deaths and serious injuries caused by traffic. The vision has been followed-up in terms of decreased mortality, but there was not a consensus on how the concept “seriously injured” should be measured at that time. The aim of this paper is to describe how to develop a measure to estimate the number of seriously injured people in Sweden. The results show that it is possible to estimate the health impact of road traffic accidents based on the definition of medical impairment. According to the results, 8389 people were seriously injured (permanently medical impaired more then 1%) in the road transport area in Sweden in 2013. If the number of people who had slipped or fallen down without any vehicle being involved is excluded, the number of seriously injured was around 4700. The result of the study has been included in the road safety goal for Sweden with the aim to have 25% less seriously injured people in 2020 than the average for the years 2006–2008. The results also showed that 91% of the seriously injured were transported by car, bike or by foot. The relatively high proportion of pedestrian fall accidents happening within the transport system irrespective of whether a vehicle was moving or not raises the question whether these types of accidents should be included in the reporting of formal road traffic accidents.