Complex sentence: The eastern part of the old line has been utilised as a footpath to Sewell and Dunstable; the western part is now part of the Leighton Buzzard Southern Bypass.
Split into simpler sentences: The eastern part of the old line has been utilised into a footpath to Sewell and Dunstable. The Western part of the old line is now part of the Leighton Buzzard Southern bypass.