I hope we will learn from past mistakes and that when Crossrail is approved a 7.1m tunnel is provided. The ability to handle all sizes of train in the future and the flexibility it gives will one day be critical.
Crossrail should be viewed as part of the national transport system and not just a solution to London's local problems.
Thameslink has already provided a model for a link that not only serves London but also reduces the need for through travellers to interchange. Too many journeys through central London are made by passengers who have no real wish to be there.
If Crossrail is to be publicly funded it will no doubt depend on resources provided by central government. We all therefore have an interest in what is to be provided and decisions cannot be made solely on the basis of local needs. Access to the CTRL at Stratford can only increase the importance of Crossrail over the wider area.
A full size tunnel would also allow for higher capacity metro operation, possibly using double deck rolling stock, which could be extended over a wider network of existing lines.
Anyone who has visited Sydney in Australia will have seen what can be achieved, with commuters from a wide area having direct access to most parts of the central core without need to change.
John Hawkins (M), 5 Anemone Court, Braiswick, Colchester CO4 5UJ