Design of traffic lights to absorb force to save people in accidents

The researchers designed traffic lights that use foam that helps absorb the kinetic energy of a crash, reducing the risk of injury and breakage in an accident.

When a vehicle hits a roadside object at an intersection, the object is most likely a traffic light. However, with the new design of the lamp post that can absorb energy, the risk of death or injury is significantly reduced.

Tests show that the new traffic light only tilts to one side on impact instead of crashing on nearby pedestrians. (Photo: University of South Australia)

Traditional traffic lights are relatively stiff and do not buckle, so a collision with a light pole can be dangerous for drivers. In addition, if the light pole is separated from the pole due to the force of the impact, it may fall on nearby pedestrians. All damaged light poles will need to be replaced. Recent data shows that in Australia, collisions with traffic lights cost $18.5 million a year in fatalities, $53.7 million in injuries and $16 million in repair and installation costs. into maintenance, says Dr. Mohammad Uddin of the University of South Australia.

Taking those numbers into consideration, Uddin and his team partnered with Impact Absorbing Systems to create a traffic light that absorbs kinetic energy. These light poles will integrate the system previously used in energy-absorbing steel mooring poles.

In that system, the bottom of each pile is located inside a cavity in the concrete foundation of the pile. The cavity is conical with the same diameter as the pile but wider at the top, creating a gap between the pile and the concrete layer. This gap is filled with polyurethane foam, which holds the stake upright until it is hit by a vehicle.

When an accident occurs, the foam is compressed while absorbing the impact force, allowing the pile to tilt to one side without breaking. Impact Absorbing Systems says the result is less impact on the driver and vehicle and less damage to the stakes.

Similar technology is being extended to use for traffic lights. The researchers hope the new pole could be ready for use this year and soon become a standard model, gradually replacing conventional poles in the future, according to Uddin.