The new Supercouncil is to build a motorway linking the two civic centres of Londonderry and Strabane.
The plan will be the first order of business for the new council which takes over from the old Derry City Council and Strabane District Council today.
The £50 million scheme will be funded by ratepayers, which will mean a 50 percent hike in rates bills over the next two years.
Construction is due to begin a year from today, April 1, 2016.
As planning now comes under control of the new supercouncil, it is able to bypass Stormont and press ahead with the plan independently.
The two-lane motorway will be the first to be built west of the River Bann in Northern Ireland.
The motorway, provisionally called the M4, will begin from the Victoria Road on the outskirts of Londonderry, pass through Newbuildings but bypass Magheramason, Burndennett and Ballymagorry, ending just outside Strabane.
The project is expected to take two years to complete and will cut journey times from an hour and a half to just ten minutes.
A spokesperson for the new Supercouncil said: “Councillors will naturally need to travel efficiently between the two centres from now on.
“It is unreasonable to expect such important people to be happy getting stuck behind tractors as they go about vital council business.
“We feel ratepayers will be happy to cough up the £50 million.”