Complex sentence: Orientated east-west, the road starts at the Causeway traveling west through the suburbs of East Perth, Perth, West Perth, and Subiaco, where the road originally terminated at the Subiaco subway under the Fremantle railway line.
Split into simpler sentences: Orientated east-west the road starts at the Causeway traveling west through the suburbs of East Perth, Perth, West Perth, Subiaco. When the road originally terminated at the Subiaco subway under the Fremantle railway line.