Farringdon will , from 2017 , be one of the country 's busiest stations ( if not the busiest station ) by number of trains passing through , being served by both Crossrail and the upgraded Thameslink route , as well as the existing Underground lines . Farringdon will , from 2018 , be one of the country 's busiest stations ( if not the busiest station ) by number of trains passing through , being served by both Crossrail and the upgraded Thameslink route , as well as the existing Underground lines .