Port Road starts at the north-western corner of the Adelaide city centre, at the intersection of North Terrace and West Terrace, and heads northwest, turning north at Thebarton to become part of the City Ring Route, before meeting Park Terrace at Hindmarsh and heading northwest again with its widened median, crossing the North-South Motorway and heading through the suburbs of Woodville and Cheltenham, before it turns northwards at Alberton to cross Grand Junction Road, changing name to Commercial Road and terminating not long afterwards in the centre of Port Adelaide.

The road includes a very wide median strip, giving a total width of approximately 70 metres.

[4] The canal and railway line were never created in the road allotment: the railway line when built in 1853 was built approximately 1 km to the east.

In the 1968 Metropolitan Adelaide Transport Study (MATS plan) the road was destined to be upgraded to become the Port Freeway.

After the change, the West Terrace end is not numbered, and it bears route R1 (city ring route) between James Congdon Drive and Park Terrace.