The St Helier Tunnel is an important link in central St Helier. It was built in the late 1960s, opening in early 1970, and passes under the rocky terrain at Fort Regent. It, along with the rest of the A17 forms a useful bypass of the town centre, giving an easier, flatter route between the A1 to the west of the town and the A3 to the east.
The tunnel is a single bore two lane tunnel with a high roof to minimise any problems with oversized vehicles. Whilst only a couple of hundred metres in length, the tunnel passes under a massive rocky bluff rising some 50m above sea level. Prior to opening the tunnel, traffic either had to pass through the narrow town centre streets, or round the southern end on the A16 and A4. The western portal was opened up by removing the end of a row of warehouses along the docks, and creating a new junction with the A1, whilst to the east the road emerges to meet a roundabout with the eastern flank of the ring road.
