The decision on the design and location of the long-awaited new M49 junction will dramatically accelerate the growth already underway at Avonmouth, according to a Bristol commercial property expert.

Highways England has announced that the preferred option for the £50 million junction is the Farm Lane Two Bridge Option, and that detailed designs will now be drawn up and subject to statutory approvals construction should begin by the end of this year.

Tim Davies, head of the Bristol office of global real estate specialists Colliers International, said: “At long last work can get underway on this vital stretch of road that will provide access for Western Europe’s biggest Brownfield development site.

“The implications of the new M49 junction for Bristol and the South West are far-reaching. This significant infrastructure improvement will provide improved access and unlock the huge economic potential of the Avonmouth/Severnside Enterprise Area, and this will in turn boost the economy of the wider Bristol area.

“Growth in this strategically-important area will now inevitably accelerate dramatically, as potential occupiers will be attracted by the benefits of direct motorway access, in addition to the existing benefits of excellent rail and port access.”

The port of Avonmouth and the Avonmouth/Severnside Enterprise Area to the west of Bristol currently have no direct access to the M49.

Mr Davies was among those who for a number of years called for a junction to link the five-mile long M49 - which stretches from Avonmouth to the second Severn Crossing - directly into the businesses located in the Avonmouth/Severnside Enterprise Area.

He pointed out: “The South West and Wales accounted for a quarter of the UK’s 10.2m sq ft of industrial take-up in the first half of 2016, and most of that resulted from major letting deals at Central Park, including The Range at 1.2m sq ft and Lidl at 600,000 sq ft.

“These deals will bring thousands of jobs to the area, and the improved infrastructure resulting from the new M49 junction will help establish the Avonmouth/Severnside Enterprise Area as one of the most sought-after industrial and logistics locations in the UK.”

The Highways Agency said the Farm Lane Two Bridge option had been selected as the preferred option because it was more affordable, required less land than the alternative option at this location, and would open up a greater area to support economic growth. Other benefits included better capacity to accommodate increased traffic levels in the future, and better suited to incorporating options for National Cycle Network, bridleway and footpaths.

The new junction will use the existing bridge at Farm Lame and a second bridge will be build adjacent to it. The two bridges will be incorporated into a single roundabout spanning the motorway with new access and exit slip roads built on both sides of the junction to connect with northbound and southbound traffic.