Although the idea was seen as imaginative, only a brief estimate of cost was given: £300 million.A feasibility study was recommended as a high priority so that the practicability and costs of the scheme could be determined.At each end of the central core, the line will divide into two branches: in the east to Abbey Wood and Shenfield in Essex, and in the west to Heathrow Airport and Reading in Berkshire.Part of one of the eastern branches, between Liverpool Street and Shenfield, was transferred to a precursor service called Tf L Rail in 2015; this precursor took control of the Heathrow Connect service in May 2018.The other eastern branch runs underground from Whitechapel to Canary Wharf and Abbey Wood.It takes over the Custom House to Woolwich via Connaught tunnel stretch of the former North London Line built by the Eastern Counties and Thames Junction Railway, and connects it with the North Kent Line via a tunnel under the Thames at North Woolwich.Crossrail's central core section will use new east–west twin tunnels under central London, splitting into two branches at either end.
Positioning a new station at Paddington presented structural design challenges due to its positioning just below Eastbourne Terrace and the station's taxi rank, and within 3 m (10 ft) of Isambard Kingdom Brunel's 150 year old mainline station.
The north–south line proposed routing West Coast Main Line, Thameslink, and Great Northern trains through Euston and King's Cross/St Pancras, then under the West End via Tottenham Court Road, Piccadilly Circus and Victoria towards Crystal Palace and Hounslow.
The report also recommended a number of other schemes including a "Thameslink Metro" route enhancement, and the Chelsea–Hackney line.
The east–west scheme was for a line from Liverpool Street to Paddington/Marylebone with two connections at its western end linking the tunnel to the Great Western Main Line and the Metropolitan line on the Underground.
The City route was shown as a new connection across the City of London linking the Great Northern Route with London Bridge.