Otros mecanismos

Based on previous pedestrian accident studies, characteristics of pedestrian accidents are reviewed from the following aspects of distribution of accident time, weather conditions, locations, demographic characteristics of victims, alcohol and varieties of accidents.

Time

Time distribution in a day in different areas is inconsistent, but 16:00 ~18:00 can be recognised as the common period when pedestrian accidents frequently happened. Most accidents happened at workdays. Variation of time distribution in a day and in a week can be attributed to different background conditions in different areas (e.g. working time, holiday time, motorisation level, etc). Time distribution of months is similar. The highest number of nationwide pedestrian fatalities happened during winter months, mainly from September to January, with typical fewer daylight hours and more inclement weather (e.g. Häckelmann, 1976; Maier, 1884; Harruff, 1997; CRTAS, 2007; etc.).

Weather

3.2 Pedestrian accident analysis 27

wet (42%). Häckelmann (1976) found that darkness and wet will increase the severity of accidents, similar to the former conclusion of “rainfall increases the risks to pedestrians by a factor of three in daylight and about nine at night ” (Smeed, 1968).

Location

Pedestrian crashes occur most frequently in urban areas where pedestrian activity and traffic volume is greater, for instance, the commercial area (shopping area, restaurant, hotel etc.) is found to be related to increasing crash risk of pedestrians (Maier, 1984; Zegeer et al., 1985).

Studies in UK (Davies, 1999) claimed that types of hazardous intersections for pedestrian crossing include high-volume, high-speed and multi-lane intersections with complex signal phasing (or without any traffic control at all). Similarly, accident data of Darmstadt (2001~2005) revealed that pedestrian accidents concentrated at intersections along main roads in the CBD area with high speeds of motorised vehicles, large numbers of public transport vehicles and tram stations or bus stops nearby.

Furthermore, pedestrian accidents happened on the arterial roads are always severer than on neighbourhood streets (Maier, 1984) due to higher vehicle speed, a study by UK DOT (1987) showed that when vehicle speed rises from 20 mi/h to 40 mi/h, the chance of pedestrians’ death in an accident increased by eight times (from 10% to 80%).

Quaye (1993) evaluated the relative safety of pedestrians crossing at T- and X-intersections and pointed out that for the same vehicle and pedestrian flows on a hypothetical intersection, X-intersections were generally found to be safer than T-intersections for a vehicle flow above 100 vehicles per hour.

Researches done in Australia (Cairney, 1999) found that nearly half accidents happened between pedestrians and near side vehicles, while 25%~30% accidents related to far side vehicles, similar results came out in Darmstadt (Germany), about 45% accidents happened at the near side, while 30% at far side based on the accident data from 2001 to 2005.

Demographic characteristics of victims

Children (5-9) especially young boys and the elderly (60+) are most possible to be involved in the accidents , males are more likely to be involved in a crash than females (e.g. Häckelmann, 1976; Maier, 1884; Harruff, 1997; CRTAS, 2007; etc.).

Those over 60 years have more fatalities than younger people at signalised intersection, which can be mainly attributed to age-related physical factors, mobility, judgement, abilities to deal with emergencies and other experiences when crossing (cf. Section 2.1.2). Reasons for more aged pedestrians being involved in intersection accidents also due to their preference of crossing at intersections (cf. Section 2.1.3).

Alcohol

Similar to other traffic accidents, alcohol also contributes to pedestrian accidents. Hughes (1998) studied situations in UK and found that more than half of the pedestrian fatalities in the age groups of 21-24, 25-34, and 35-44 involved intoxicated pedestrians (55%, 57%, and 55% respectively). A study in the U.S. demonstrated that nearly one quarter of the fatalities were positive for alcohol (Harruff, 1998).

Vehicle types involved

Consequences are different when pedestrians are crashed with different types of vehicles, generally the heavier the vehicle, the more serious is the consequence, for example, accidents with trams are nearly 1.5 times severer than those with cars (Häckelmann, 1976).

Bus-related accidents are common, either because pedestrians violates the signal to catch a bus or the bus blocks the visibility between the pedestrian and the striking vehicle (Harkey, 2004).

There is a special kind of accidents involving Heavy Good Vehicles (HGVs) in UK. Of thirty-one accidents, four involved elderly pedestrians being hit while crossing the road directly in front of a HGV when the vehicle driver started to move from stop line, without seeing the pedestrians (Hughes, 1998). It is also proved by Robinson (1997), 16% of fatal pedestrian accidents involving HGVs were of this type.

Vehicle movements involved

Based on previous studies (e.g. Häckelmann, 1976; Harkey, 2004), more than 75% of pedestrian accidents occurred with through traffic and the consequence was normally severer than accidents with turning traffic, because speeds of through traffic were higher. Most of these accidents can be ascribed to pedestrian non-compliance including violating signals or crossing outside crossings. Studies in the U.S. declared that approximately one out of five accidents at signalised intersections involved a turning vehicle hitting a pedestrian and the split between left-turning and right-turning accidents was about 60/40 (Robertson,1984). Similar situation exists in Darmstadt (2001~2005), crashes with turning traffic take the percentage of 15%, more than half of the turning-related accidents are involved with left-turning vehicles. Häckelmann (1976) found that the consequence of accidents with left turning vehicles are three to four times severer than with right turning vehicles. Most accidents involved turning traffic are mainly due to structural deficiencies , which results in high speed of turning vehicles and driver failing to yield to pedestrians.