ITARDA INFOMATION

  This chapter introduces rear-end accidents in which car occupants suffered whiplash injury.
The data were collected by ITARDA itself in the Tsukuba area of Ibaragi prefecture. None of the cars presented here had active head restraints (AHR).

  1) Case 1: Head restraint positioned too low
        (Fig. 10 and 11)

  Passenger Car A (male driver aged 19) was traveling in the high-speed lane of a 6-lane highway (4-lane at the accident site) at about 80 km/h. Passenger Car B (male driver in his 30s), traveling in the lane to the left of Car A at about 60 km/h, moved into Car A's lane to avoid Car C entering the highway. Turning on a right-turn signal, the Car B driver checked the right rear for safety but failed to notice Car A . The Car A driver slammed on the brakes too late and rammed into Car B. Car B rebounded and collided into the left curb.
  The Car B driver suffered cervical injury, or whiplash, that took 14 days to heal. His push-in type head restraint was in the lowest position. Car B's damage in the rear was insignificant. The driver of Car A was not injured.

Fig.10 Collision diagram of Case 1

Fig.11 Head restraint of Car B (Case 1)

  2) Case 2: Head restraint positioned too low
        (Fig. 12 and 13)

  Passenger Car A (male driver in his 60s) was traveling at about 40 km/h on a 2-lane road. The preceding Passenger Car B (female driver in her 20s) stopped to turn right. The Car A driver did not notice that Car B had stopped until 10 m behind, and then applied the brakes hard but smashed into Car B.
  The Car B driver sustained whiplash that took 14 days to heal, as well as lumbar injury. Her head restraint, a push-in type, was positioned rather low. Car B's damage in the rear was small. The Car A driver suffered minor lacerations to the face upon hitting the steering wheel.

Fig.12 Collision diagram of Case 2

Fig.13 Head restraint of Car B (Case 2)

  3) Case 3: Head restraint removed
        (Fig. 14 and 15)

  Passenger Car A (male driver in his 40s) was traveling at approximately 60 km/h on a 2-lane road. The preceding Passenger Car B (female driver aged 18) was at a halt at the end of the stalled traffic. Noticing the traffic stall too late, Car A slammed on the brakes 20 m short of Car B but crashed into the rear.
  The Car B driver and her passenger (female aged 19) sustained minor whiplash. The driver's and passenger's head restraints had been both removed, thus totally unable to prevent the heads from snapping backward. Car B's damage in the rear was not extensive. Car A driver was not injured.

Fig.14 Collision diagram of Case 3

Fig.15 Head restraint of Car B was removed (Case 3)

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Institute for Traffic Accident Research and Data Analysis (ITARDA)