|其他题名||Pedestrian Safety in Crossing Roads: Human Factors and Safety Assistance Design Strategies|
|导师||吴昌旭 ; 张侃|
|关键词||行人安全 人因 情境意识 违规行为 安全辅助设计|
|其他摘要|| Pedestrian safety, especially safety in crossing roads has been a challenge for many developing countries, including China. Among contributing factors like roadway environment and vehicle design, human factors in pedestrian and drivers played a vital role in pedestrian crashes. Therefore, this thesis surveyed important human factors that should be concerned in promoting pedestrian safety when crossing roads, and further explored design strategies for safety assistance.|
Human factors in pedestrian safety on the drivers' aspect mostly concerned with drivers' situation awareness, i.e. their perception, interpretation and prediction of pedestrian behaviors, thus it is crucial to understand pedestrian behaviors to facilitate drivers' situation assessment. In line with this goal, Study 1 modeled pedestrian paths in crossing unmarked roadway as a result of dynamic decision making in balancing perceived risk and crossing efficiency. The model was calibrated and validated with real data, and has good fitness. Study 2 explored how pedestrians could use gestures to communicate their intention to cross road at uncontrolled crosswalks to facilitate driver interpretation. Eleven gestures were evaluated by drivers in terms of visibility, meaning, clarity, familiarity and courtesy, of which four were tested in real scene. Experiment shows that the gesture with left arm bent and hands level were effective in promoting driver yielding behavior, while cause no significant increase in side effects.
On the pedestrians' aspect, one critical countermeasure to increase pedestrian safety is to reduce pedestrian violations in signalized crosswalks, including running against red light and violation at the clearance phase. Since pedestrian perceived waiting time is an important determinants of their red light running behaviors, Study 3A and 3B aims to decrease their perceived waiting time via display design of signal lights. More specifically, Study 3A explored pedestrian information needs in wafting red light, as the attention-gate model of duration estimation suggest that when people are distracted on non-temporal information, their estimated duration will be shorter. Survey results shows that among the four types of information pedestrian mentioned, pedestrian preferred the information relate with road crossing task most, followed by context information, learning and appreciation information. Pedestrians generally pose a negative preference towards public entertainment information. Further analysis shows that females and highly educated people have higher preference over context information than their counterparts.
Study 3B reduced pedestrian perceived waiting time from a different approach, given that time estimation in daily life has greatly relied on external temporal clues, and researchers in HCI has found effects of different progress bars on perceived duration. The experiment compared pedestrians estimated duration of red light strips with five types of counting down styles. Pedestrians seem to report waiting time based on the time distribution feature at the early phase of red light, and has a lower estimation when stripes at early phase has shorter durations.
Pedestrian violations at clearance phase have been observed in some previous work, but predictors and countermeasures of this type of violation haven’t been explored. Therefore, before developing countermeasures in Study 4B, an observational study of pedestrians' choices after their arrival at the clearance phase (in China, it means flashing green phase, FG) was conducted in Study 4A. Among the 486 pedestrians observed, 85.2% committed a violation, and have significantly more conflicts with vehicles. Binary logit model suggest that a pedestrian is more likely to violate during FG when they are younger, has no secondary tasks, at the different side of the intersection with stopped vehicles, there has been more people crossing the street and those crossers were farther from destinations when the pedestrian arrived, and speed requirement for them to cross successfully (time remained/road width) was lower.
Although pedestrian are more likely to wait when speed requirement is higher, 78% of the pedestrians choose to cross the road even when speed requirement is as high as 7m/s. Since pedestrian made their crossing decisions based on the remained time on the counting down lights, Study 4B explored whether this clue has induced risky decisions in pedestrians, and compared it with an alternative clue: speed requirement. Experiment in simulated crossing at real sites suggests that "remained time" do induce more complacent judgments of one's ability to finish crossing during FG than “speed requirement”. Compared with "remained time", "Speed requirement" resulted in much more conservative judgment criterion, which is compatible with pedestrians' real capability, and assisted pedestrians to have better ability to discriminate the crossing difficulty in various scenarios.
Findings in this thesis not only improved understanding of pedestrian behaviors in crossing roads, but also have important implications for designing in-vehicle pedestrian protection systems to assist drivers, and user-centered design of traffic lights, which will finally improve pedestrian safety
|庄想灵. 行人过马路安全中的人因及安全辅助设计策略研究[D]. 北京. 中国科学院研究生院,2015.|