The public inquiry into the M4 relief road will begin on 1 November, Economy and Infrastructure Secretary Ken Skates has announced.
The Welsh government has backed plans to build a £1.1 billion six-lane motorway south of Newport to relieve congestion.
Mr Skates said that it was in Wales’ interest to have an independent review into whether the proposals form part of the long term, sustainable solution to the traffic problems at this gateway to Wales.
He said: “I was keen to ensure that a date was set for the public inquiry into the M4 project at the earliest possible opportunity in order that we can provide clarity on the process.
“It’s been clear for some time that for businesses, commuters and visitors alike, the current stretch of M4 around Newport is unable to cope with the needs of modern Wales.
“This inquiry will provide open and transparent scrutiny of our proposed solution, and suggested alternatives, before providing vital feedback to inform a final decision on whether we proceed to construction.”