Complex sentence: Stepps has served as a commuter town for Glasgow, which is a short journey from its centre by train on SPT's Cumbernauld Line, or by the A80 road.
Split into simpler sentences: Stepps has served as a commuter town for Glasgow. The town is served by a railway station on SPT's Cumbernauld Line, providing a quick commute to central Glasgow, and by the A80 road.