The start date for the five-month public inquiry into the proposed £1bn M4 Corridor around Newport has been delayed until next year.
The inquiry was due to start on 1 November, but now Welsh government officials have said it will start by 31 March 2017.
The introduction of a revised methodology to forecast traffic growth by the Department for Transport has caused the delay. The Welsh Government said this change was not shared with it and it needs time to consider the new data.
The delay will not impact the due completion date of 2021, said the Welsh Government economy and infrastructure secretary Ken Skates.
The inquiry will look at all aspects of the road plan and take into consideration the most up-to-date and accurate information, as well as alternatives. Costain, Vinci and Taylor Woodrow with consultants Arup and Atkins, make up the design development team, supported by environmental consultant RPS.
“The UK Government has already expressed its desire to see work on the M4 project start as soon as possible, so it is hugely disappointing that the Department for Transport chose only to engage with us on these amendments to their traffic forecasting three days before they were introduced, forcing this regrettable delay to the start date of the public inquiry,” said Skates.
“Whilst we push forward with our metro plans for North and South Wales, the long-standing and continued problems associated with the M4 around Newport need a solution that delivers a long-term, integrated and sustainable transport system.
“Assessments indicate that our proposed M4 project is the only reasonable solution, but it is only right and proper that the proposals are scrutinised robustly, transparently and openly in an inquiry and that we test the project in light of the most up-to-date information available to ensure that we deliver the right choice for the people in Wales.”
A Department for Transport spokesperson said: “We keep our traffic forecasts under review and made clear to Welsh officials at the start of this year we were going to update our projections.
”We are committed to working closely with the Welsh Government and encourage them to deliver this project which will improve journeys for drivers.”