THE surface of one of the most notoriously damaged stretches of the Northern Distributor Road (NDR) failed because its popularity with heavy vehicle drivers was underestimated, according to technical services director Chris Devitt.
Orange City Council are spending $480,000 to dig up 300 metres of the NDR from the Leeds Parade roundabout to Clergate Road and replace it with an 18.5 centimetre layer of hot mix asphalt.
Mr Devitt said the 300 metre stretch of road was the area of the NDR most in need of repair, but other sections would follow later in the year as part of major works on the bypass.
He blamed the damaged surface on pavement settlement caused by its location on an embankment leading up to the concrete bridge over the rail track.
“We’ve maintained it as it settled to ensure it remained trafficable but it needs a more comprehensive solution instead of patching,” he said.
Mr Devitt said it was unusual for a road surface to need complete replacement within eight years, but he was confident the new hot mix surface would be a 20 year solution.
“Road pavement does wear out at various rates,” he said.
“In reality we’ve probably had a number of heavy vehicles more than we anticipated... the bypass has been very successful.”
The road surface could be damaged again if settlement reoccurs, but Mr Devitt said the fix chosen would allow extra layers of asphalt to be added.
“We won’t get anywhere near the amount of deflection that did occur,” he said.
He said the council had chosen a more expensive means of repairing the road to get the work done as quickly as possible while still providing a “long-term fix”, with drivers only expected to be inconvenienced for five days. One lane of the NDR will stay open at all times.
After the work near Leeds Parade is finished, the next three months work will get underway on more than $750,000 worth of upgrades on the NDR surface near Burrendong Way, between Forbes Road and the Mitchell Highway.
Mr Devitt said work to improve the camber of the Leeds Parade roundabout would also occur later this financial year.
The upgrades are part of more than $5-million to be spent on roads in the current financial year.
Work will occur in daily stages with each section re-opened to traffic at night to minimize the impact on drivers.