Commuters contending with "already unacceptable" levels of overcrowding on trains face increased rail capacity problems in the next four years and beyond, a report by MPs has warned.
The Department for Transport's (DfT) latest plans show that all the relevant targets for increasing the number of passenger places on trains by March 2014 will be missed.
There will be 15% fewer extra places delivered in London in the morning peak and 33% fewer into other major cities.
This is in comparison with the numbers the DfT said would be needed just to hold overcrowding at current levels, the report from the House of Commons Public Accounts Committee said.
The report said it is "not clear to passengers where the money from increased fares has been spent".
On some parts of the Southeastern franchise, where high-speed Javelin services operate, "passengers are paying premium fares to support new services which do not stop at their stations and do little to alleviate overcrowding on the trains they use", the MPs said.
The committee said the DfT's knowledge of how many people use which parts of the rail network and when is "inadequate and sketchy".
The MPs recommended that the DfT should require all new train carriages to be fitted with automatic passenger counting equipment to show how many people are travelling on which trains and when.
Rail franchisees should provide "useful and verifiable data" from the counting exercise, the committee said.
The report said the current round of planning had relied heavily on buying extra carriages and extending platforms to accommodate longer trains, "but this approach cannot go on indefinitely".