There are a couple of rail crossings passing through Marion Road, with the Glenelg Tram Line having a level crossing in Plympton between Anzac Highway and Cross Road, with the three crossings causing major congestion during peak times. In Park Holme, the Noarlunga Line crosses over Marion road with an overpass.
The A14 commences at the intersection of Marion Road and South Road. It travels north for the entire length of Marion Road. At Henley Beach Road, it takes a dog leg to the west on Henley Beach Road for about 250 metres, and then continues north along the entire length of Holbrooks Road. At Grange Road it take a 50-metre dog leg to the east, and then continues north along the entire length of East Avenue until it terminates at Port Road.