Complex sentence: London Underground now plans to increase the frequency to 36tph by 2019, enabling one train every 100 seconds between North Greenwich and West Hampstead, with 27tph in off-peak periods between Willesden Green and Stratford.
Split into simpler sentences: London Underground now plan to increase the frequency to 36tph by 2019. This will provide a train every 100 seconds between North Greenwich and West Hampstead with 27tph in off-peak periods between Willesden Green and Stratford.