A respected civil engineer has called for an urgent examination of New Zealand’s parking buildings, after the recent incident where a motorist drove straight off a four-storey carpark.
Structural engineer John Scarry says modern parking buildings are supposed to have effective barriers against cars that lose control, but not all buildings comply with modern engineering standards.
“You can make a pretty good case for immediately checking the barriers on every parking building in New Zealand. However, my immediate concern is barriers designed and constructed prior to 2002.[1]”
“I don’t doubt that older parking buildings met the standards of the day, but the standards of the day may not be sufficient. Some older parking buildings appear to have no effective protection against a car being driven off the edge. In some cases there is little more than wire mesh to stop a possible fatal plunge off the building.”
“The accident in Newmarket is a clear warning - all existing barriers should be checked and replaced or upgraded where required, even on newer buildings.”
Scarry adds that city councils could use existing laws to force building owners to upgrade their carparks if the barriers were found to be inadequate.
“Sections 121 and 124 of the Building Act allow the territorial authorities to identify high-risk buildings and require immediate work to be done to reduce or remove the danger.”
Road safety campaigner Clive Matthew-Wilson, who edits the car review website dogandlemon.com, believes accidents of this kind are likely to increase, along with our ageing population.
“Most modern cars are automatics, so, if you accidently select the wrong gear, you can end up flying forwards or backwards without much warning. This type of accident is common among the elderly and among inexperienced drivers.”
He adds:
“As a matter of common sense, parking buildings should be required to protect car occupants from common mistakes. Otherwise, it's only a matter of time before people die."
Release ends (see also the photograph below, showing a carpark building in Fanshawe Street, Auckland, which appears to have little more than wire mesh protecting the occupants from driving off the building).
[1] For light traffic area carparks, the New Zealand loadings standard AS/NZS 1170.1:2002 specifies the following horizontal design forces on car park barriers, to allow for accidental impact:
Normal barriers - 30 kN (equivalent to 3 tonnes or 3000 kg),
Barriers at the end of long downward ramps - 240 kN (equivalent to 24 tonnes or 24000 kg).
Additional factors increase these actions, and the resultant force must not exceed the ultimate strength of the barrier system.
Even the 30 kN force on a normal barrier is significant, and is a considerable increase over the load specified in the loadings standard between 1992 and 2002, which was only 10 kN, and even then, the 10 kN only applied in the absence of wheel stops.
