Car to pole impacts account for a large proportion of car occupant casualties in many motorized countries. Each year in Australia about 2000 vehicles crash into timber power poles resulting in approximately 100 fatalities and 1000 serious injuries at a community cost of about A$500 million. The estimates for North America are over 1000 fatalities and over 100,000 serious injuries each year, with an estimated 10-fold increase in costs. Historically the primary countermeasure used by road safety authorities has been to move utility/power poles away from the roadside. While this may reduce the risk of an impact, moving the position of the timber pole has little effect on the outcome if an impact occurs. To reduce the risk of injury there is a need to change the properties of the pole, so that the pole acts to stop the car while retaining integrity ensuring that neither becomes an unrestrained hazard.

This paper presents the results of a program aimed at developing a utility pole that absorbs energy and yields sufficiently to stop the vehicle in several metres at survivable decelerations with no intrusion into the occupant space. This has been achieved by using composite materials supplemented with built in energy management systems. To test the impact properties of the prototype, we conducted ten fullscale frontal crash tests using a variety of car sizes at impact speeds of 50, 80 and 100 km/hr. The performance of the poles during the tests was monitored using multiple high-speed cameras, and accelerometers were fitted to the vehicles on later tests.

The results demonstrate the superior impact performance of the composite poles and the ability of these poles to safely stop impacting vehicles even at high impact speeds, while retaining enough integrity to ensure cables carried by the poles remain intact and supported above the ground.

This superior impact performance carries substantial potential safety benefits. Furthermore, the projected whole of life costs of the composite pole are less than existing timber poles. The lighter weight and lower cost of the poles also assists the primary countermeasure of relocation away from the road. Limitations of the preliminary test program are the lack of instrumented test dummies that means that these results cannot be communicated directly in terms of injury criteria. However the reduced decelerations measured in the vehicle, and the retention of the occupant compartment even in the highest test speeds strongly indicates likely reduction in injury risk.

The composite pole used in these tests start as a standard production utility pole already in limited use in North America. It is then enhanced to absorb energy in a controlled manner, prevent unrestrained hazards and can keep the power/communication cables supported. Widespread use of these composite poles could prevent considerable serious injury, death and associated community cost.