London Midland rail services hit by sickness and signalling issues
More than 20 London Midland rail services have been affected by staff shortages and signalling problems.
Staff shortages has led to eleven cancellations between Watford Junction and St Albans Abbey.
Passengers in the West Midlands were warned of possible delays of up to an hour because of signalling problems.
The problems affected routes in the West Midlands, Worcestershire, Staffordshire, Gloucestershire, Bristol, Derby and Sheffield.
A London Midland spokeswoman said: "Today's disruption of services is due to short notice sickness."
"The problems that we've been having with a shortage of drivers have been fixed."
She urged people to use National Rail Enquiries and look at the London Midland website.
More than 950 services were delayed or cancelled between 14 October and 10 December.
The government has told the firm to offer £7m in benefits as passengers have been hit by weeks of cancellations and delays due to a driver shortage.
This includes season ticket holders getting five days of free travel passes.
On Thursday Transport Minister Norman Baker said he was confident the firm had now rectified the driver shortage.
But he added the firm had fallen short of its franchise obligations and the government would continue to monitor its performance and "take firmer action if necessary".