The Capacity Strategy is a written document adopted by each Infrastructure Manager (IM) that sets out its expectations regarding future developments in the demand for and supply of rail infrastructure capacity, as well as its strategic vision for accommodating those developments. It serves as a common basis for communication, consultation and coordination with operational stakeholders throughout the Advance Capacity Planning process.

The Capacity Strategy introduces the geographical scope of the network covered by strategic capacity planning and outlines the planned development of physical infrastructure, including construction, upgrades, renewals and decommissioning.
It also contains information on the applied principles in connection with traffic and Temporary Capacity Restriction (TCR) planning. The pre-announcement of TCRs with major impact is also integral path of the Capacity Strategies.  The Capacity Strategies are published in draft from 39 months before the beginning of the concerned timetable period and in final form at X-36 months before the beginning of the concerned timetable period.