The New Zealand Transport Agency has conducted a school bus limited speed sign trial in Ashburton, with the aim of developing measures that would reduce vehicle speeds near school buses picking up or dropping off children.
The initial trial of the school bus signs ran from May 2013 to April 2014.
A second trial, designed to establish the size of a sign that would fit and was effective on smaller school buses, was approved by the agency from February 2016 and must be completed by February 28, 2017. Both trials were limited to Ashburton district roads.
Over eight years ago, about 20 flashing warning signs displaying the 20kmh speed limit for passing parked school buses were provided to Ritchies Transport, but they were taken off at the direction of the Ministry of Transport.
An agency spokesman said when Oamaru began using the signs, they were not approved for a trial and a trial would have addressed the bigger picture.
"It is not just installing a sign, but including education and an information campaign around it so local people know that something has changed.
"It also needs to be evaluated in order to get the best value for money of any new system or signs.''
He added that when Oamaru's buses were operating with the signs almost a decade ago, they were permanently displayed as 20kmh, which implied that was the limit whenever a driver passed a bus.
"This could have had unintended consequences upon passing traffic.''
The spokesman said the signs for the Ashburton trial were approved and followed a legal process.
"They are only displayed when the legal speed limit applies and the entire trial has been monitored so that we will know the benefits [or otherwise] of these signs.''
Agency Southern regional director Jim Harland said the trial of 20kmh signs on school buses in Ashburton showed a reduction in the speed of traffic passing a school bus which had stopped to let children on or off, but there was still work to do to determine the specification for signs on smaller buses.
"The key finding from the work so far is that a safe and sustainable reduction in speed past school buses can only be achieved with a combination of community engagement, education and enforcement as well as the electronic speed limit signs, which are active only when the speed limit legally applies, fitted to all school buses in the district.
"Earlier trials of signs without the support of the community and police indicated that without all of these elements, the speed variation of traffic passing school buses may increase the risk rather than improving safety.''
