The number of heavy vehicles crossing the Rakaia River Bridge is increasing.
Data obtained from Waka Kotahi’s current weigh-in-motion site, built in the road in 2015, shows a 17 per cent increase in the number of heavy vehicles from 2018 to 2022.
Originally the weigh-in-motion site was proposed to be used to collect data for all vehicles travelling over the Rakaia Bridge with a camera for automated number plate recognition to allow the identification of trucks that are overloaded, travelling over speed, or that have unpaid road user charges.
However, a Waka Kotahi spokesperson said the particular system was unable to match up vehicles with possible overweight loads for potential prosecutions, given the higher bar required for accuracy.
What it has done is provide an accurate traffic flow count, differentiating heavy and light vehicles.
Heavy vehicles have a gross vehicle mass (GVM) of more than 3500kg while light vehicles have a GVM of under 3500kg.
In 2018 the weighbridge recorded 694,622 heavy vehicles, which was 14 per cent of the total traffic flow – with 4,189,426 (86 per cent) light vehicles.
Last year heavy vehicles totalled 826,246 which was 16 per cent of the total with 4,368,218 light vehicles.
That equates to a 17 per cent increase in heavy traffic from 2018 to 2022 across the Rakaia Bridge but only a 2 per cent rise in the total traffic flow, with light traffic increasing by 4 per cent from 2018 to 2022.
With the Fairfield Freight Hub set to be constructed this year, the number of heavy vehicles will drop in future.
The site at Fairton will see an increase in containers moved via rail and is estimated to cause a reduction of around 40,000 truck movements per year.
The freight hub is scheduled to be completed by the end of 2023.
The Selwyn District Council supports the new split site Commercial Vehicle Safety Centre (CVSC).
Ashburton District Mayor Neil Brown raised his concerns at the increased safety issues around retaining the southern site between the rail overbridge and the Rakaia River bridge, but the facilities are being built outside of his jurisdiction at the southern tip of the Selwyn District.
Selwyn District Council’s group manager development and growth, Tim Harris, said the council is pleased Waka Kotahi had addressed the concerns raised by key stakeholders on the original proposal to use a single southern site “which would have created additional vehicle turning movements and safety risks near the Rakaia Bridge”.
“The addition of a north bound CVSC site nearby, along with the original southern site, has addressed this,” Harris said.
Waka Kotahi obtained resource consent from the Selwyn council in December 2022 Harris said to alter its state highway designation and be able to include the second site.
“During the application process, Waka Kotahi fully consulted with the council which resulted in conditions placed on them that include the upgrade of a local adjoining road, which will be used for site access, and to produce an operational management plan.”
- Jonathan Leask