A Window Possession allows mandatory trains to transit the section as planned and restricts access for
ad hoc traffic.
Ad hoc services may be:
• restricted from operating within the Possession times or;
• allowed to operate under specified conditions as agreed by the Possessions Coordinator and
Requester.
Operating restrictions or alternate systems of safe working, excluding Temporary Speed Restrictions
(TSRs), should not be implemented at the conclusion of a Window Possession. If it can be reasonably
forseen that operating restrictions or alternate systems of safe working will be required following
fulfilment of the Possession, a Window Possession is not appropriate.