Preparation work can now begin on the £152m Portishead to Bristol line which will bring the 5.5km disused rail line back into use and see a car and bus interchange built at Portishead.
The project is a key part of the first phase of the MetroWest programme of transport improvements across the region being led by the West of England Combined Authority and North Somerset Council.
The reopening of the Portishead to Bristol line is hoped to solve the congestion gridlock faced by thousands of motorists who battle to get in and out of the growing town each day.
The DCO decision follows an agreement between North Somerset, the Combined Authority and the Department for Transport to collectively pledge £36m in additional funding to the project after projected costs rose.
The additional funding and the start of construction remains subject to a full business case being signed off.
Over the next 18 months, the project will complete its detailed design, undertake ecology-enabling works and, finally, submit its full business case to the Department for Transport and the Combined Authority and North Somerset Council.