Periodic review 2018 (PR18) glossary and explanatory documents

This page contains our PR18 glossary, explaining terms used in PR18 documents, and other explanatory documents.

Explanatory documents

The PR18 ‘building block’ methodology pdf icon PDF, 64 Kb


Control periodThe period over which Network Rail is be expected to deliver specified regulatory outputs for the funding that we allow it.
CP4Control period 4 (1 April 2009 to 31 March 2014)
CP5Control period 5 (1 April 2014 to 31 March 2019)
CP6Control period 6 (which we expect to run from 1 April 2019 to 31 March 2024)
DfTDepartment for Transport
ERTMSEuropean Rail Traffic Management System
ETCSEuropean Train Control System
FDMFreight Delivery Metric, which measures the percentage of freight trains arriving at their destination within 15 minutes of their scheduled time, covering delays for which Network Rail is responsible.
Financial frameworkThe financial framework includes our approach to incentivising and monitoring Network Rail's financial performance, during a control period.
GSM-RGlobal System for Mobile communications - Railways
HLOSHigh-level output specification
HS2High Speed 2
Incentives frameworkThe incentives framework includes the incentives we place on Network Rail and train operators (and which also act on other parties, such as suppliers) to encourage them to deliver good outcomes for passengers, freight customers and taxpayers. The structure of charges, Schedules 4 and 8 and REBS are all part of this framework.
Interim reviewIf, during a control period, we decide that the criteria in track access contracts for reopening the determination have been met (e.g. in the event of a major increase in costs), we can decide to carry out an 'interim review' and issue a new determination.
ORROffice of Rail and Road
OutputsRegulated outputs are what Network Rail is expected to deliver in return for its funding, during a control period. Outputs can include specific improvements in operational performance and increases in capacity, as well as projects that enhance the railway.
Periodic reviewKnown as an 'access charges review' in the Railways Act 1993, a periodic review takes place typically every five years. It involves us determining what Network Rail must deliver in the next control period and the funding it should be allowed for this.
PossessionsNetwork Rail needs to restrict access to its network to carry out many of its maintenance and renewals activities (e.g. a closure of a section of track). These restrictions of access are referred to as possessions.
PPMPublic Performance Measure, which is the proportion of trains that arrive at their final destination within: five minutes for London & South East and regional services; or ten minutes for long-distance services.
PR08The 2008 periodic review (relating to CP4)
PR13The 2013 periodic review (relating to CP5)
PR18The 2018 periodic review of Network Rail (relating to CP6)
RABRegulatory Asset Base
RDGRail Delivery Group
REBSRoute-level Efficiency Benefit Sharing mechanism.
 This provides participating train operators with an incentive to work with Network Rail to reduce infrastructure costs at the route-level in return for a share of the efficiency gains (or losses).
Revenue requirementThe level of revenue that we determine Network Rail needs to run its business and deliver its regulated outputs.
SBPsNetwork Rail's Strategic Business Plans, which are submitted to ORR for scrutiny and set out what the company proposes to deliver and the costs associated with doing so.
Schedule 4The regime in track access contracts that provides incentives on Network Rail in respect of planned possessions so that it can undertake engineering work, and which provides payments to train operators for the financial impact on them.
Schedule 8The regime in track access contracts that provides incentives on Network Rail and train operators to avoid and manage unplanned service disruption, and which provides payments to other train operators for the financial impact on them.
SettlementThe term used in our initial consultation on PR18 to refer to the set of decisions that we plan to make for each route, and potentially other parts of Network Rail, that would form a key part of the determination that we set Network Rail.
SoFA / Statement of funds availableThe Secretary of State/Scottish Ministers' statement setting out the public funds that they expect to be available (or likely to become available) to support the achievement of what the Secretary of State/Scottish Ministers want delivered by the railway in the corresponding control period (the latter being set out in the HLOS).
System operatorThe centrally based system operator function within Network Rail covers activities such as timetabling, capacity allocation and long term planning.
The ActThe Railways Act 1993