What information can the bumper in a vehicular accident provide?

• A. Point of impact and braking
• B. Speed and acceleration
• C. Airbag deployment location
• D. Seat position during impact

Answer: (B)

The bumper’s damage signature is a primary clue about how much energy the car had to absorb in a crash. The front bumper and its energy-absorbing crumple zones deform in proportion to the energy released during impact. Since the energy involved in a crash is related to the vehicle’s speed at impact (kinetic energy is proportional to velocity squared), more/greater crush suggests a higher impact speed. The way the bumper collapses also reflects how quickly that energy was dissipated, which corresponds to the deceleration the vehicle experienced. In other words, by studying the depth and pattern of the bumper’s intrusion and crumple, investigators can estimate both the speed at impact and the rate of deceleration (acceleration in crash terms).

The other aspects—exact point of impact, airbag deployment location, or seat position during impact—are not reliably determined from bumper damage alone, so the bumper provides the clearest information about speed and deceleration.