Increase in transport demand put strain on Ruapehu road network
The increased volume of trucks on Ruapehu’s road network is putting pressure on the District’s aging rural bridges and causing concerns for Council.
Council has needed to advise Heavy Commercial Vehicles (HCV) to avoid travelling between SH4 and SH30 on Poro O Tarao Rd as a bridge about 1.3km north of Waimiha between Waimiha Village and Waimiha Valley Rd has weight and speed restrictions in place until further notice.
The bridge is currently restricted to 60% of Class 1 loads at a maximum speed of 10kph meaning that most loaded HCVs will not be able to cross it.
Ruapehu Team Leader Land Transport Warren Furner said that last week Council received an engineer's report after the bridge was reported as making “strange noises” as vehicles went over it.
“Council's Engineers inspecting the bridge advised the need to immediately put weight and speed restrictions in place until repairs could be affected,” he said.
“Engineers are working toward replacing damaged components to restore the bridge to its full capacity and are investigating options for a longer term solution that may include replacing the bridge.”
Mr. Furner noted that the impact that increased numbers of HCV's and High Productivity vehicles (50max) trucks would have on Ruapehu’s road network has been recognized for some time.
For example, “From 2015 it was estimated that 36,500 hectares of forestry plantation was going to start reaching maturity.”
“The harvest which is starting to get underway is anticipated to yield up to 24 million tonnes of timber which needs to be transported out of the District,” he said.
“Logging trucks cause as much wear and tear to our rural road network during the harvesting period as dairying and sheep and beef farms do over a lot longer period of time.”
“The bridge in question had a programmed maintenance/replacement schedule based on usage of less than 150 vehicles per day with less than 10% of these being HCVs.”
“With the upsurge in forestry trucks it has been seeing around 170 vehicles per day with 30% of these being HCV’s.”
Mr. Furner said that to help compensate Council adopted a Forestry Differential Rate to support the Land Transport activity as part of the 2015-25 Long Term Plan (LTP).
“This doesn’t actually mean Council has more money for road maintenance but that the forestry block owners pay a bit more in rates toward our planned work programme.”
“Council will be working with NZTA to determine if the bridge can be given a special emergency classification to get government funding toward its replacement.”