The number of log trucks rolling over on New Zealand roads has been cut by nearly half following the introduction of new
safety measures in recent years, according to a study commissioned by the Land Transport Safety Authority (LTSA).
The decline in rollover crashes is documented in a study conducted by Transport Engineering Research Limited New Zealand
(TERNZ) comparing log truck rollover crashes for the periods July 1996 to June 1997 and July 1999 to June 2000.
The TERNZ study found a 48 percent reduction in rollover crashes from 1996-1997 to 1999-2000. Over the same time the
number of log trucks on the road increased from 650 to 935, meaning that on a per vehicle basis the incidence of log
truck rollovers has reduced even further, by 64 percent.
After a spate of log truck crashes in 1997, the LTSA identified truck rollover as the main problem. Since that time
several safety initiatives have been introduced in conjunction with the Log Truck Safety Council, the Road Transport
Forum and police to improve log truck stability and reduce the number of crashes.
Measures include restrictions on the height of log loads and a campaign to cut the cornering speeds of log trucks to at
least 10 percent below posted advisory speeds. Forest owners have now agreed to stand down log trucks belonging to
operators whose vehicles continue to speed or carry unsafe loads.
Director of Land Transport Safety Reg Barrett applauded the efforts and asked drivers to be patient when they encounter
slow moving log trucks on the road.
"These trucks are keeping their speeds
down to make the roads safer for everyone, but that benefit can be erased when other drivers overtake dangerously. Many
of these vehicles are unable to pull over onto the shoulder safely to let traffic pass. We're asking people to use a
little patience and wait until the next passing lane, where it is safe to overtake."
Long-term safety measures for log trucks have included the completion of a stability assessment of the entire log truck
fleet. A points rating system is being developed to help operators modify or replace poorly performing vehicles.
There are also signs that the stability assessments of log trucks have helped cut the overall crash rate for all heavy
vehicles. The TERNZ study attributes a 45 percent reduction in the incidence of rollovers for the entire combination
vehicle fleet to a better understanding of vehicle stability resulting from the log truck initiatives, along with
improvements to roads and vehicle technology.
Mr Barrett said heavy vehicle safety would be further improved by new stability standards proposed in the draft Vehicle
Dimensions and Mass Rule, now in development. He also cited the development of a new operator safety rating scheme as
cause for optimism.
"This is a system we're developing with the Road Transport Forum which will help us objectively measure a company's
historic safety performance in terms of its drivers, vehicles and management. It will allow us to reward good performers
with lower compliance costs and give poor performers the choice of improving or losing their licence to operate."