Complex sentence: This part of the road is currently of a lower standard than further south, sandwiched between the shoreline of the loch and the mountains to the west, and runs generally alongside the West Highland Line.
Split into simpler sentences: This part of the road is currently of a lower standard than the sections further south. It is sandwiched between the shoreline of the loch and the mountains to the west, and it runs generally alongside the West Highland Line.