A consultancy has been appointed for detailed planning of sections of the Inland Rail.

The ARTC has announced the appointment of an international planning and engineering consultancy to investigate and design the work.

The company selected is WSP Australia, a subsidiary of Canada-based WSP Global, one of the world's largest professional services companies.

WSP Australia will deliver the reference design and approvals documentation for the 173-kilometre Stockinbingal to Parkes track enhancement project.

This will involve ecological and geotechnical surveying as well as looking at impacts to cultural heritage, noise, air quality and utilities.

ARTC project director Melvyn Maylin said procurement of construction contractors would follow after WSP had completed its reference design and planning approvals.

"We expect to tender for first packages of work for the Stockinbingal to Parkes project in late 2021," Mr Maylin said.

"The work will involve modifying structures in this section of track to accommodate the height and width of double-stacked freight trains.

"Some of the works we're planning include increasing the vertical clearance on the Lachlan River Rail Bridge in Forbes, increasing vertical clearance under the Wyndham Avenue Road Bridge in Forbes, and building a new crossing loop north of the Daroobalgie Road level crossing," Mr Maylin said.

"Other clearance and safety works include modifying Forbes Railway Station and several existing crossing loops, structures and utilities along the line."

WSP Australia has also been appointed to do the reference design and approvals documentation for the 185-kilometre Albury to Illabo section of the Inland Rail.

As with the Stockinbingal to Parkes section, this will be an enhancement of the existing rail corridor. It will include enhancements to rail tracks, footbridges and road bridges, overhead structures, signal structures and level crossings.

Mr Maylin said the benefits of combining the two Inland Rail projects into the same service provider package is that both sections are enhancement projects in existing rail corridors, rather than new construction.

"By nature, they are similar types of work and this approach will lead to cost effective and efficient project delivery," he said. "WSP will bring substantial experience in major infrastructure investigation and design.

"The Albury to Illabo section has been classified significant infrastructure by the NSW Government, and is currently in the process of an environmental impact statement approval pathway.

A recent Ernst and Young report claimed Inland Rail will better link regions to national and global markets and generate new opportunities for producers and industry.

EY estimated southern NSW would get an increase of nearly $4 billion in gross regional product throughout Inland Rail's first 50 years of operation.

There would be an increase in supply chain efficiencies, it said, and new investment opportunities in specific industries including food and fibre manufacturing, distribution and logistics hubs and expanded airports.

This would be especially good news for city centres like Albury-Wodonga and Wagga Wagga, which would act as hubs for surrounding regional industry.

Under the Inland Rail plan, Cootamundra and the Bethungra Spiral will be bypassed by a new 37 kilometre section of rail to create a new direct route from east of Illabo tracking north to Stockinbingal.

Inland Rail's website says the route open up a more efficient way to transport freight through the area.

"A two-kilometre wide study area has been identified and approved by the Australian Government," the website says.

"This project is currently in the reference design stage. During this time, we are conducting various studies and consulting with landowners and other key stakeholders to finalise plans for this project."

For information about the Inland Rail in Southern New South Wales, visit the Inland Rail projects website at https://inlandrail.artc.com.au/projects