Case Studies

Monash University found a number of interesting safety facts about Coslee light poles.

"The pole would present an acceptable low risk of injury to vehicle occupants in the frontal crash ride down, wearing an inertia seat belt in a typical semi-compact vehicle."

Department of Civil Engineering
Impact Absorbing Pole Crash Test Results Coslee 002-07 Page 2 of 34
EXECUTIVE SUMMARY
This report presents the results of a crash test into a VicRoads specified 11.0m (12.5 metres
including spigot and arm) Impact Absorbing Pole Assembly. The report details the vehicle used, the
pole’s dimensions, the test setup, how the vehicle was guided into the pole, acceleration and video
test results, pre and post crash test pictures and results assessment.
The pole is designed to provide positive protection under a 60 km/h impact according to the
VicRoads Impact Absorbing Street Lighting Pole Test Specification TCS 014-3-2001. The criterion
in the VicRoads Specification essentially requires that a vehicle of 1200 kg mass impacting the pole
at 60 km/hr will produce decelerations, measured at the vehicle floor pan, no greater than 10g
averaged over any 50 millisecond period, nor greater than 10g for any period longer than 10
milliseconds. The pole must collapse on vehicle impact in a predictable and acceptable manner,
deform progressively so as to decelerate an impacting vehicle at a controlled rate and finally bring it
to rest whilst still in contact with the pole, and the base of the pole is to remain attached to the
footing after impact.
The vehicle was brought to rest by the pole within a distance of around 2.2 m and remained in
contact with the pole. The pole remained connected to its base for 0.27 of a second until the speed of
the vehicle had reduced to around 2 m/sec (7.2 km/hr) and the vehicle had travelled around 2.0
metres over the pole where upon the pole severed from its base. The vehicle yawed slightly
clockwise 25 degrees to the passenger’s side. The vehicle trajectory after collision with the pole
would most likely not intrude into adjacent lanes. The pole fell over perpendicular to the direction of
the vehicle’s path prior to impact and on the side on which the 20kg luminaire was mounted, i.e. on
the passenger side.
The VicRoad’s deceleration criteria were exceeded in that the deceleration averaged over 50
milliseconds was around 1.9 g’s above the 10 g’s required (11.9 g’s), and the maximum specified
deceleration averaged over a 10 millisecond period exceeded 10 g for 35 milliseconds instead of
being less than 10 milliseconds.

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