Spatio-temporal accident analysis for accident prevention in relation to behavioral factors in driving: The case of South Anatolian Motorway

Analyzing the pattern of traffic accidents on road segments can highlight the hazardous locations where the accidents occur frequently and help to determine problematic parts of the roads. The objective of this paper is to utilize accident hotspots to analyze the effect of different measures on the behavioral factors in driving. Every change in the road and its environment affects the choices of the driver and therefore the safety of the road itself. A spatio-temporal analysis of hotspots therefore can highlight the road segments where measures had positive or negative effects on the behavioral factors in driving. In this paper 2175 accidents resulted in injury or death on the South Anatolian Motorway in Turkey for the years between 2006 and 2009 are considered. The network-based kernel density estimation is used as the hotspot detection method and the K-function and the nearest neighbor distance methods are taken into account to check the significance of the hotspots. A chi-square test is performed to find out whether temporal changes on hotspots are significant or not. A comparison of characteristics related driver attributes like age, experience, etc. for accidents in hotspots vs. accidents outside of hotspots is performed to see if the temporal change of hotspots is caused by structural changes on the road. For a better understanding of the effects on the driver characteristics, the accidents are analyzed in five groups based on three different grouping schemes. In the first grouping approach, all accident data are considered. Then the accident data is grouped according to direction of the traffic flow. Lastly, the accident data is classified in terms of the vehicle type. The resultant spatial and temporal changes in the accident patterns are evaluated and changes on the road structure related to behavioral factors in driving are suggested.     

Drivers’ engagement level in Adaptive Cruise Control while distracted or impaired

Adaptive Cruise Control (ACC) is designed for convenience to maintain a set speed and specified distance from a lead vehicle. However, use of ACC may change driving patterns and perceptions over time. Many drivers perceive safety benefits associated with ACC even though the safety implications are not always clear. This study examined the factors that can influence the frequency of ACC use with surveys distributed to ACC owners in Washington State. A cluster analysis was conducted to group drivers based on how often they activated and used ACC under various driving scenarios. Four clusters emerged that showed a range of use from those who rarely used ACC in any situation (low engagement group) to those who used it for almost all situations regardless of whether it is appropriate or not (high engagement group). An ordered logit model was used to predict the likelihood of being in one of the four clusters. Drivers that were less likely to use ACC in distracting or impaired situations tend to be older, were not willing to re-purchase a similar vehicle with ACC, and were generally confused on how to use the cruise speed setting. Drivers who reported higher overall use of ACC also used the system in situations that can be considered distracting or risky, which can negate the overall benefits of ACC.     

Look where you have to go! A field study comparing looking behaviour at urban intersections using a navigation system or a printed route instruction

In this study, experienced navigation system users (N = 20) drove a given unfamiliar route twice: once with the navigation system activated and once with a printed instruction including a route instruction. Quantitative analysis indicated that drivers passed intersections slower when they used the printed instruction than when they used the navigation system. Drivers looked more often and in proportion longer to the side scene when they used the printed instruction and made less and proportionally shorter glances away from the road scene and to the instruction than when they were supported by the navigation system. No difference was found between these two conditions in the total number of glances and the amount and duration of glances to the forward scene. A qualitative analysis provided understanding of the quantitative results: the type of route guidance was identified to influence drivers’ motive for scanning the side road scene. When the navigation system was used the motive was primarily to look for potential hazards and when the printed instruction was used the motive was more focused to look for salient orientation points. The outcomes of the study are discussed in terms of looking motive and the ‘look but failed to see’ phenomenon.     

Factors affecting perceived safety and enjoyment based on driver experience

A positive driving experience, especially for older drivers, increases the attention to the emotional dimensions of driving, such as the driver’s perceived safety. Therefore, this study empirically presents factors affecting driver experience and compares them between older and younger drivers. Consequently, we conducted a face-to-face survey on elderly and young drivers and analyzed the data of 246 drivers using structural equation modeling. The analysis presented measurements and structural model evaluations. Considering the analysis, it was found that driving-related information and car-exterior context affect the perceived safety and enjoyment of a driver’s experience. Additionally, car-exterior context exerts a greater influence on the perceived safety and enjoyment of the elderly drivers’ group than the young drivers’ group. The results of this study will empirically contribute to the satisfaction of driver experience and perceived safety improvement in the future. It also provides a basis for the development of driving interfaces to improve the quality of the driving experience of the elderly.