The Portway is a trunk road, approximately 6.5 miles (10.5 km) long, which links central Bristol, England, with its port at Avonmouth. It is part of the A4 road, which was the primary east west highway in Southern England before the construction of the M4 motorway.The road starts at the Junction of Bridge Valley Road & Hotwell Road Hotwells and runs through the Avon Gorge, parallel to the serpentine path of the River Avon.