Complex sentence: This railway line formerly continued to Staines-upon-Thames political and transportation efforts are periodically made to re-use the southern part of it for a Heathrow Airtrack rail link from the counties south of London to Heathrow Airport.
Split into simpler sentences: This railway line formerly continued to Staines-upon-Thames. Efforts are periodically made to re-use the southern part of it for a Heathrow Airtrack rail link from the counties south of London to Heathrow Airport.