no79 2009
Fatal collisions in low speed ranges: 
Why are pedestrians killed in low-speed collisions?
  In recent years we have seen a steady decline in the total death toll from traffic accidents and in the number of fatal accidents involving pedestrians. Among the various possible reasons for the latter, one of the most influential and direct factors is the lower collision speed. This is attributable to strengthened traffic regulations and roadside crackdowns on speeding as well as widespread driver education, reducing the cases of driving over the speed limit or reckless high-speed driving and consequently reducing the number of dangerous traffic accidents in which pedestrians are hit at high speeds.
On the other hand, however, there has been a gradual yearly increase in traffic accidents involving cars driving at low speeds and correspondingly in the proportion of this type of accident in the total number of fatal cases.

In order to reduce pedestrian fatalities, we need to formulate and implement effective measures not only to help lower the collision speed at the time of an accident but also to prevent the death of pedestrians hit by a low-speed car.

In this issue of ITARDA Information, defining the collision speed of 20 km/h or lower as the "low speed range", we analyze the reasons why many pedestrians are killed even when hit by a car driving in the low speed range, and discuss what drivers and pedestrians should do to avoid these fatal collisions.
Note that, because Japan's traffic accident statistics do not list collision speeds, the speed at which the driver recognizes the danger of a traffic accident is taken as the collision speed instead (hereafter the "speed at the time of danger recognition"), and the accident data used in the present study is limited to that with a record of the speed at the time of danger recognition and with pedestrians as the primary or secondary party injured or killed.

1. Statistical data on low−speed collisions involving pedestrians
2. Degree of danger of collisions in the low speed range
3. Characteristics of low-speed collisions (1)
 −Time and place−
4. Characteristics of low-speed collisions (2)
 −Pedestrians and vehicles involved−
5. Characteristics of low-speed collisions (3)
 −Highly dangerous cases−
6. Case studies


  [Characteristics of fatal collisions in the low speed range]

* Fatal collisions occurring in the low speed range account for 67% of the total traffic accidents involving pedestrian casualties and 17% of those involving pedestrian fatalities in 2007, and are expected to increase in the future.
* Daytime urban areas are the major site of these accidents, especially at intersections, for the speed range of 11−20 km/h and at open traffic spaces for the speed range of up to 10 km/h.
* Females are more likely to be involved, and small children and seniors are more susceptible to being killed.
* Low-speed collisions are particularly dangerous for small children 0−5 years old, leaving a high fatal accident rate.
* Large-sized and box-shaped vehicles are particularly dangerous in these accidents.
* Highly dangerous combinations are:
- Elderly pedestrians crossing the road vs. box-shaped vehicles making a right turn, knocking them down on the road
- Elderly pedestrians crossing the road vs. large-sized vehicles just starting, running them over
- Elderly pedestrians in parking lots vs. standard-sized vehicles backing up, running them over or hitting them hard
- Small children and elderly pedestrians in parking lots vs. standard-sized vehicles just starting, running them over
- Elderly pedestrians crossing the road vs. large-sized vehicles making a left turn, knocking them down under the vehicle body, running them over, or hitting them hard

[Reasons for causing death at low speeds]

So far we have seen how pedestrians are easily killed in low-speed collisions due to hitting their head directly on the A-pillar or other hard part of the vehicle, violently hitting the road after being knocked down, or being run over. The risk of death is even greater for vulnerable seniors or small toddlers and in the case of box-shaped vehicles or large-sized vehicles with a flat front and a long distance from the ground to the lower end of the vehicle body.

[What we should do to prevent the occurrence of low-speed collisions]

Effective measures to reduce the collision speed are under way, such as designing a road shape that naturally reduces the vehicle speed, putting humps on the sides of the road, installing devices for communication between the road and the vehicle for early detection of pedestrians, and developing and introducing an automatic braking system as one of the active safety technologies. The most effective and important thing, however, is that every driver and pedestrian should always keep safety in mind, continuously check what is happening all around, and act wisely to avoid traffic accidents.

In reducing the number of accidents involving small children, it is important that parents or other responsible persons always keep an eye on the children and teach them not to run into the roadway or go into dangerous areas, so that they will never become the victim of a fatal accident "while you look away for just a second".

As seen in the case studies above, drivers in most low-speed collisions did not notice the pedestrian until it was too late. Typically, drivers pay too much attention to oncoming vehicles when making a right turn, and overlook pedestrians as a result. On the other hand, in many cases, pedestrians may start to cross a road without checking for turning vehicles because the light is green. Many traffic accidents could be prevented if both the driver and the pedestrian take a little time to confirm safety.

It is also important for pedestrians to actively protect themselves by wearing conspicuous clothing or using reflective materials, and for drivers to turn on their headlights at dusk to ensure that they are not overlooked. Many low-speed collisions can be avoided if either party notices the other.

Institute for Traffic Accident Research and Data Analysis (ITARDA)