It has short southward branches to Littlehampton and Bognor Regis, which offer direct services to and from London.

The electrification of the tracks further west in the late 1980s enabled electric trains to travel the whole route via Netley to Southampton or via Botley to Eastleigh.

The London and South Western Railway ran the tracks west of Farlington Junction, north of Portsmouth, by the inland shore of Langstone Harbour.

The West Coastway line runs almost alongside or within a few miles of the south coast of Sussex and Hampshire, between Brighton and Southampton.

Regular services run from London Victoria via Gatwick which avoid Brighton by using the tunnel between Preston Park and Hove.

Prior to the 1980s electrification of the "(south) Hampshire lines", including the part of this line west of Farlington, they were operated as a separate entity terminating at Portsmouth – few trains traversed the Cosham to Farlington triangle which lies north of Portsmouth and Langstone Harbours, except a daily Brighton-to-Exeter through (direct) train.

The lines now operated under the banner "West Coastway" have a complex history and were built in stages by five different companies between 1840 and 1889.