Rail passengers in Bucks will face further disruption this week because of strike action.
Due to planned ASLEF industrial action no train services will run across the entire Chiltern Railways network this Friday.
Pre-booked tickets can be used on Thursday 31 August or up to and including Tuesday 5 September.
Meanwhile, customers are also reminded that the railway between Aylesbury and Princes Risborough will remain closed until Sunday 29 October.
This closure will enable HS2 to construct over a mile of track and signalling equipment, allowing the new high-speed line to pass beneath the existing railway to the south of Aylesbury.
Chiltern Railways will be operating an hourly rail replacement service in each direction during the closure, including additional services from September when schoolchildren return after the summer holidays.