Office of Rail and Road glossary of terms.


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AC systems

A line equipped with OLE system supplying alternating current to electric trains.

Accident frequency rate

The number of Reporting of injuries, diseases and dangerous occurrences regulations 2013 (RIDDOR) incidents per 100,000 hours worked


Association of Community Rail Partnerships.


Access charge supplement.


Access dispute resolution rules: Rules which govern the handling of rail disputes arising from matters covered by the Network Code.

All lane running (ALR) motorway 

A type of motorway design where the hard shoulder is permanently converted to a running lane, with refuge areas available for drivers to use in an emergency. It also deploys technology, such as overhead electronic signs, which can be used to set variable speed limits and display messages to drivers. 


The term 'alliances' is being used to describe a wide range of different relationships from project-based partnerships through to potentially long-term and comprehensive commercial arrangements covering a wide range of activities carried out by Network Rail's regions train operators. The common factor is that Network Rail and a train operator reach agreement to work together more closely and share the benefits of doing so, within the framework of their existing individual accountabilities and responsibilities. Alliances do not involve the creation of new legal entities such as formal joint ventures.


Asset Management Excellence Model.

Annual Incentive Plan

The annual incentive plan (AIP) uses a mix of corporate, business and individual objectives to determine individual awards. It is designed to enable participants to be able to clearly identify and establish how they can influence the performance of the organisation and as a result their potential awards.


An automated open level crossing with barriers

Asset management/assets

Network Rail is required, as a railway licence holder, to develop and apply the policies and criteria it will apply in respect of the maintenance, renewal, replacement, improvement, enhancement and development of the relevant railway assets, and make appropriate information about those policies and criteria readily accessible to persons providing services relating to railways and funders.

The company is also required to maintain appropriate, accurate and readily accessible information about the relevant assets, including their condition, capability and capacity.

Effective asset management supports the delivery of this promise by planning, delivering and making available an infrastructure that supports the current and future timetable safely, efficiently and sustainably.

Railway assets include: tracks, signals, tunnels, bridges, viaducts, level crossings and stations.

Asset management/assets [highways]

Asset management is a term used to describe the approach taken by an organisation like National Highways to gain value from the assets it manages. When we refer to assets, we tend to refer to the physical features of a road, such as safety barriers, lighting columns or bridges. However, assets may also refer to the vehicles and equipment that National Highways operates, or the computer systems it uses, or even the data it collects and manages. 


The Association of Train Operating Companies (ATOC) was an incorporated association owned by its members. It was set up by the train operating companies, formed during privatisation of the railways under the Railways Act 1993. As well as being the official voice of the passenger rail industry, it also provided its members with a range of services that enabled them to comply with conditions laid on them in their franchise agreements and operating licences. These included the National Rail Enquiry Service (NRES) and Railcard marketing.

ATOC's principal activities included assisting members to co-operate on developing and managing projects that benefited passengers and to promote the advantages of the rail network.

With effect from 24 October 2016, each of the ATOC companies operate under the single name of the Rail Delivery Group.


Automatic train protection.

Automatic Half Barrier (AHB)

A level crossing where the half barrier equipment is automatically activated by the approaching train.


Automatic warning system.

Axle counter caused-delays

Axle counter caused-delays – Baseline - Basic visual inspections – Blockade


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The position at this point a year ago.

Baseline [highways]

Value of funding available for a named major enhancement scheme or category of expenditure.

Basic visual inspections

The visual inspection of infrastructure without the use of any equipment. They are key elements of Network Rail’s arrangements for ensuring that the infrastructure remains safe for the passage of trains.


The variety of plant and animal life in a particular habitat. This can be measured in biodiversity units through the biodiversity metric, published by Natural England.


The closure of a route for an extended period, typically more than a weekend, usually to allow engineering works.

Bottom up workbank

A detailed work plan driven by the condition or capability of an asset.

Bow-tie analysis

The BowTie Method. A BowTie is a diagram that visualises the risk you are dealing with in just one, easy to understand picture. The diagram is shaped like a bow-tie, creating a clear differentiation between proactive and reactive risk management.


Building Research Establishment Environmental Assessment Methodology - an environmental assessment method and rating system for buildings.

Broken rail

A rail which has a fracture through the full cross section or a substantial piece broken out of the railhead.


British Transport Police: a police service for rail operators, their staff and passengers in England, Wales and Scotland.

Business Critical Rules (BCR)

Business Critical Rules provide an overall structure for determining what Network Rail must do and who needs to do it. They are being designed from risk-based principles - understanding the things that can go wrong and what must be done to prevent them.


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Capital expenditure: it refers to the funds used by Network Rail to acquire or upgrade physical assets on the railway and related infrastructure in order to maintain or increase the scope of their operations. Such expenditure is referred to as Renewals (of existing infrastructure e.g. works that will provide long term benefits such as replacing a section of track) or Enhancements (upgrading existing or building new infrastructure, e.g. electrification of a railway line).

CAPEX [highways]

Capital expenditure refers to the funds used by National Highways to acquire or upgrade physical assets on the strategic road network in order to maintain or increase the scope of their operations. Such expenditure is referred to as renewals (of existing infrastructure, e.g. works that will provide long term benefits such as replacing a section of road surfacing) or enhancements (upgrading existing or building new infrastructure, e.g. a junction improvement or bypass). 


Civils asset register and reporting system.


Cancellations and Significant Lateness (CaSL): the proportion of trains which arrive at final destination greater than 30 minutes from planned arrival, or full/part cancelled or missed calls.


Cost benefit analysis.


Competition Commission.

The CC conducted in-depth inquiries into mergers, markets and the regulation of the major regulated industries, undertaken in response to a reference made to it by another authority.

The Competition Commission closed on 1 April 2014. Its functions have transferred to the Competition and Markets Authority (CMA).


Closed-circuit television.

Change of aspect - NFF

An unintended change of aspect (the colour shown - red, yellow, green) by the signalling system, which when tested, could not be found to be faulty. (No Fault Found.)

(Signalling systems are designed to 'fail safe' with any change always being to a more restrictive aspect, e.g. yellow to red.)


CHARM is the Common Highways Agency Rijkswaterstaat Model – a national traffic and incident management solution that combines the functions of existing software systems controlling roadside devices, traffic data and incident response.


Confidential incident reporting and assessment system; an industry funded but independent system which enables workers to whistle blow confidentially.


A term describing only those responsible for structures such as bridges.

Civils adjustment mechanism

A process used in PR13 that required Network Rail to submit its civils asset management plan 2016/17-2018/19  to ORR so we can form a judgement on the volumes and unit costs of the work that will be funded.

Class representative committee

The committee charged with considering and approving changes to the Network Code under part C of the code.


The Railways (Class and miscellaneous exemptions) Order 1994 exempts, among other things, certain named railway assets and categories of railway assets from the licensing provisions of the Railways Act 1993 (as amended).

CO2 equivalent (CO2e)

Many gasses other than CO2 contribute to climate change. Methane has 25 times the warming effect of CO2, so one tonne of methane would be 25 tonnes of CO2e. CO2e allows different greenhouse gas emissions to be brought under one number.

Composite reliability index (CRI)

It provides an indication of the contribution of asset reliability to the safety and performance of the railway.

Condition of track (COT)

This is a reason for a restriction below normal speed which ensures that trains pass at a safe speed over a track or a bridge or an embankment which is not currently fit for line speed. 

Conductor rail

The 'third rail' on mainline railways that provides DC electric power to trains. In the UK this system is used in the south of England and on Merseyrail. It can be badly affected by ice and snow in the winter. ORR Safety principles for train servicing work in conductor rail premises.

Conflict point

The location of converging tracks where two trains can no longer pass each other without making contact.

Control period

A control period is the period to which an access charges review (e.g. a periodic review) applies. Control periods are typically five years in length, but maybe shorter or longer depending on what the regulator decides as part of the review.

  • CP7 covers from 1 April 2024 to 31 March 2029
  • CP6 covers from 1 April 2019 to 31 March 2024
  • CP5 covers from 1 April 2014 to 31 March 2019
  • CP4 covers from 1 April 2009 to 31 March 2014
  • CP3: 1 April 2004 to 31 March 2009
  • CP2: 1 April 2001 to 31 March 2004
  • CP1: from the privatisation of Railtrack to 31 March 2001

Cordon cap

Places an obligation on Network Rail to provide only a certain number of train paths through the cordon (route), even if the train operating company (TOC) has rights that would exceed this limit.

A cordon cap is implemented when the total number of access rights to a path, if used, would exceed the remaining capacity of the network.

Covtech technology

A secondary automated audible warning at a crossing to enhance the Whistle Board (a white circular sign with a grey edge and black W in the centre that indicates to a train driver that they must sound the horn or whistle and is often used to provide a warning to users of accommodation crossings, footpath crossings and occupation crossings).


Cost Performance Index is a ratio of budgeted cost of work performed to date against actual cost to date.


Crown Prosecution Service.

CRR [highways]

Central Risk Reserve is a central risk pot to cover portfolio level cost risks in addition to base funding, which might include funding for project and programme risks.


Channel Tunnel Safety Authority.

Cyclic top

Cyclic top is a series of dips or vertical irregularities in one or both rails. When a train passes over these dips vehicles can experience a bouncing motion which in severe cases can cause the wheels to leave the rails and lead to a risk of derailment.


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Delay Attribution Board: Body that manages and oversees the effectiveness and accuracy of the delay attribution process and the use of the Delay Attribution Guide (see below). Also considers proposed amendments to Delay Attribution Guide and provides guidance to rail industry parties to assist in the resolution of disagreements concerning delay attribution.

DAPR (previously known as 'DAG' Delay Attribution Guide)

Delay Attribution Principles and Rules: Document that provides guidance on the attribution of delay, between parties, across the network.


Design, build, finance and operate. Contracts for the improvement and operation of Trunk Roads undertaken by Private Finance Companies (see PFI).

Deemed minutes

A pre-determined value in delay-minutes given to the cancellation of a train.

Defective rail

A rail which has any fault requiring repair or replacement within a timescale commensurate with the nature of the defect.

Delay minutes

Incidents which cause delays to trains produce delay minutes. Network Rail delay minutes represent the total number of minutes delay to passenger and freight trains, where the cause of delay is attributed to Network Rail. The minutes are allocated to relevant parties as set out in the DAPR (see above).

Delivery plan

National Highways' plan, which sets out in detail how it will deliver its strategic outcomes and measure success.

Delivery units (DUs)

Network Rail’s maintenance teams based in geographic locations across its network.


When a train's wheelset runs off or leaves the track.

Designated funds

A series of ring-fenced funds to address issues over and above traditional road investment.

Design Manual for Roads and Bridges (DMRB)

Standards, advice notes and other documents relating to the design, assessment and operation of trunk roads, including motorways.

Development Consent Order (DCO)

The Planning Act 2008 introduced a new development consent process for Nationally Significant Infrastructure Projects (NSIPs). A Development Consent Order (DCO) automatically removes the need to obtain several separate consents, including planning permission, and is designed to be a much quicker process than applying for these separately. Applications for DCOs are decided in accordance with National Policy Statements (NPSs) by the Planning Inspectorate for England, which considers applications and makes recommendations to the Secretary of State who then decides whether to grant consent for a proposed scheme.


Department for Transport

Disaggregated detail

In November 2011 Network Rail completed devolution of power for running the railways to its ten operating routes. In order to ensure transparency, Network Rail produce and publish detailed financial and operational performance information for each of the routes.


Docklands Light Railway.


Disabled person's protection policy. A licence requirement under the passenger and station licences. DPPPs are the vehicle for operators to set out, for passengers and the ORR, their commitments and standards of service provision, as well as relevant policies and practices, with regard to people with assistance needs using the rail network. They will also provide an overview of the accessibility of the operators’ facilities and services.


Drainage assets are those that collect, move or store surface water runoff from the strategic road network, such as drains, gullies, pipes and retention ponds.


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East Coast Main Line - the railway line between London King's Cross and Edinburgh.

Eddy current testing

A system using electromagnetism to detect and assess discontinuities in metal; adapted specialist technology to categorise maximum crack length and depth in every metre of rail..

EEA State

A state within the European Economic Area, i.e. the European Union (EU) member states, Iceland, Liechtenstein and Norway.


An improvement in the relationship between inputs and outputs (the final product delivered) or outcomes (the measured impact of the output) achieved. Efficiency is typically recognised, for example, against a target, when a company delivers more outputs or greater outcomes for the same funding or where it delivers its outputs/outcomes for less funding. 

  • Embedded Efficiency - As used in Highways sector: Reduces the funding required at project level and is already built into the post-efficient business plan. Embedded efficiency applies to projects and programmes of work that had a defined scope and schedule when the dSBP was drafted, or outputs against which Efficiency and Inflation Monitoring Manual 8 efficiency can be measured and against which post-efficient cost baselines have been set.
  • RP2 Generated Efficiency - As used in Highways sector:  Does not reduce the funding required for the current road period, but will, in general, benefit later road periods or reduce risk within RP2. This type of efficiency will apply to the areas of the plan that did not include an efficiency challenge in the dSBP and were therefore left as pre-efficient cost.
  • Carry Over Efficiency - As used in Highways sector: Efficiency that has been identified and secured in the previous road period, but is also realised in the current road period. Carry over efficiency currently applies to efficiencies from all RIS1 projects and programmes with expenditure profiles which span the road periods that have been captured, audited and reported using the RP1 detailed register approach and assurance process.

Engineering possession

A period of time during which one or more lines are blocked to trains to permit work to be carried out on or near the line.

Enhancement schemes

Schemes to change to network outputs, usually involving construction, that improves network capacity or capability (e.g. enabling higher speeds, allowing heavier loads) relative to the level of network outputs funded at the last relevant periodic review. Usually outputs are required at specific times (in contrast to most renewals). Network Rail enhancement projects are listed in its Enhancements Delivery Plan which is updated quarterly.

Enhancement schemes [highways]

Construction schemes that improve existing network capacity, capability, safety, outputs and outcomes.  They are scoped to be delivered with a specified timeline and budget. Each RIS specifies a programme of enhancement schemes and National Highways' Delivery Plan details how and when these will be delivered.


European Railway Agency.


European rail traffic management system.


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Failed to calls

Incidents where a train failed, for several possible different reasons, to make a timetabled stop at a station.

Failure to use

A provision of part J of the Network code which deals with a TOC's failure to use Quantum firm rights (see below). A failure to use occurs if a TOC fails to secure one or more Train slots in respect of its Quantum firm rights or a TOC fails to use a train slot included in the working timetable (see below) and which relates to a Quantum firm right.

Failure to use notices

A notice issued by ORR if it considers that there is a Failure to use by a TOC.  The notice details certain rights which the TOC is required to surrender in relation to its Failure to use.

Fatality and weighted injuries

The common way of measuring harm to passengers, workers and the public on Britain's mainline railway.


Specially cast or forged steel plates used in pairs to join two rails.

FOC on FOC/TOC delay

Delay caused by a train operated by a freight operator to a train operated by another freight operator/passenger train operator.


Freight train operating companies.

Freight Delivery Metric (FDM)

This measure tracks the punctuality of freight services at destination as well as taking into account Network Rail caused delays.

Freight Joint Board

This board consists of Network Rail and freight operators. It is not a regulatory requirement, but was set up after the Freight Recovery Board had discharged its duties relating to an enforcement order ORR issued in January 2012.

Freight measure

Incidents which cause delays to trains produce delay minutes. Network Rail delay minutes represent the total number of minutes delay to passenger and freight trains, where the cause of delay is attributed to Network Rail.

ORR published a freight measure for the period 1 April 2014 - 31 March 2019 (CP5) that is targeted at the issues which concern freight customers the most.

Freight recovery board

The freight recovery board was set up in line with our enforcement order in January 2012, with the purpose of promoting improvements to freight service performance (reducing delays to freight services) and protecting the interests of freight customers. The remit of the freight recovery board was to agree reasonably practicable steps Network Rail should take to remedy the licence breach of condition 1 of their licence (network management) and review the delivery of those steps within the timescales set out in the order. ORR confirmed in October 2012 that Network Rail has met the terms of the January 2012 freight performance order.


Fatality and Weighted Injury index: the common way of measuring harm to people on Britain's mainline railways.
The fatalities and weighted injury ratio used is: one fatality = 10 major injuries = 200 class 1 minor injuries (where the injured person is taken directly to hospital) = 1,000 class 2 minor injuries = 200 class 1 shock and trauma injuries = 1,000 class 2 shock and trauma injuries.


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"Geographic and Infrastructure Systems" - A major database of railway infrastructure assets containing information on the physical location of track, buildings and structures.


Geotechnical engineering is a discipline of civil engineering that considers the behaviour of rocks and soil. Geotechnical assets include earthworks below the road surface and that support adjacent land, such as cuttings or embankments.

Green zone

An area of protection for workers, which separates work on the railway line from train movements. The simplest way of arranging such a zone is to stop movements of all trains on all lines at the location concerned.

Fencing off the work area may be an acceptable alternative but requires reduced speed operation.


Guide to railway investment projects. A Network Rail formal procedure through which every investment project on Network Rail’s network must pass. It consists of a number of stages; at the end of these a review is carried out and if the project cannot meet the pass criteria it is stopped or held until it does. Stage 2 is pre-feasibility which describes the changes to be made to the railway to meet an output definition.


Global system for mobile communications - railway. An international wireless communications standard for railway communication. Provides a secure communication link between a train and the signaller.


Great Western main line – the railway line between London Paddington, Bristol and Swansea.


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Hand Arm Vibration Syndrome.

High output renewals

A system for renewing track or ballast cleaning using high output plant. See Network Rail's website.

Highways Monitor 

The unit within the Office of Rail and Road with responsibility for monitoring the performance of National Highways and holding it to account.


High level output specification:- A key feature of an access charges review. Under Schedule 4 of the 2005 Railways Act, the Secretary of State for Transport (for England and Wales) and Scottish Ministers (for Scotland) are obliged to send to ORR a high level output specification (HLOS) and a statement of funds available (SoFA), to ensure the railway industry has clear and timely information about the strategic outputs that Governments want the railway to deliver for the public funds they are prepared to make available. ORR must then determine the outputs that Network Rail must deliver to achieve the HLOS, the cost of delivering them in the most efficient way, and the implications for the charges payable by train operators to Network Rail for using the railway network.

Hot weather preparedness

Taking steps to ensure that the railway network is not adversely affected by high temperatures.


Health and Safety Executive.


Health and Safety at Work etc Act, 1974.


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International Liaison Group of Government Railway Inspectorates.

Improvement notice

A notice issued under the Health & Safety at Work Act setting out an improvement required in a prescribed timescale.

Independent reporters

The role of the independent reporter is to provide ORR with independent, professional opinions and advice relating to Network Rail's (as the railway licence holder) provision or contemplated provision of railway services, with a view to ORR relying on those opinions or advice in the discharge by ORR of its functions.

Informed traveller

Timescales that allow train operators to advertise timetables twelve weeks in advance in normal circumstances. See T-12.

Infrastructure incident

An event involving Network Rail owned infrastructure which may delay normal train operation.


Any device other than a pad intended to prevent a current in the rails returning to earth.

Intercity Express Programme (IEP)

An initiative of the Department for Transport (DfT) to procure new trains to replace the InterCity fleets on the East Coast Main Line and Great Western Main Line.

Intercity Express Train (IET)

Trains specified by the Department for Transport under the Intercity Express Programme. The IETs have been built by Hitachi and run on the GWML and the ECML. 


Investments cover all enhancements but also include major projects such as route upgrades or renewals.

Investment plan 

The part of the road investment strategy that sets out the planned investments and the funds available for the road period.


The International Road Assessment Programme is a registered charity dedicated to saving lives by eliminating high risk roads throughout the world. iRAP develops the star rating method of measuring the safety of a particular stretch of road.


Institution of Railway Signal Engineers.


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Joint performance improvement plans (JPIPs) were based on a two-way obligation of Network Rail and the train operating company (TOC) to improve performance.


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Key performance indicators (KPI) 

The performance specification sets out the key performance indicators. Applied to roads, they are used to measure National Highways' performance in any given road period.

Killed or seriously injured (KSI) 

A person killed or seriously injured in a road traffic collision.


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Linear asset decision support tool.

Lane 1 (2,3…) 

Lane 1 is the left most lane on a carriageway, an overtaking lane would be Lane 2, and the outside lane of a 3-lane motorway would be Lane 3 and so on. The left most lane when travelling in the opposite direction of travel would start with Lane 1, 2, 3 and so on.

Level 1 assurance

Essentially these are checks (by section managers).

Level 2 exceedance

A discrete fault in the alignment, level or gauge of the track, which requires corrective action within defined timescales.

Level crossing failure

An incident where a level crossing has developed a fault sufficiently serious for its effective and safe operation to be compromised.

Light maintenance services

"Light maintenance services" are defined in section 82(2) of the Railways Act 1993 as services of any of the following descriptions:

  1. the refuelling, or the cleaning of the exterior, of locomotives or other rolling stock;
  2. the carrying out to locomotives or other rolling stock of maintenance work of a kind which is normally carried out at regular intervals of twelve months or less to prepare the locomotives or other rolling stock for service.

Lineside structure defect

An incident where a lineside structure has developed a fault affecting its effective operation or the operation of the railway. Such structures include signal gantries and fences.


Light maintenance depot (for locomotives and rolling stock). This is any land or other property which is normally used for or in connection with the provision of light maintenance services, whether or not it is also used for other purposes.

Location cabinet

A small steel cabinet placed at the lineside housing power supplies and other equipment related to signals, track circuits and telecommunications.


Section 83(1) of the Railways Act 1993 defines "locomotive" as follows:
"any railway vehicle which has the capacity for self-propulsion (whether or not the power by which it operates is derived from a source external to the vehicle)".


London Underground Ltd, part of Transport for London.


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Moving annual average - the average of the last 13 four-week time periods.


Section 82(5) of the Railways Act 1993 provides that, in that section, "maintenance" includes the detection and rectification of any faults.

Maintenance [highways]

The requirement to maintain the public highway is set out in the Highways Act 1980. Maintenance is work that takes place to ensure that roads are safe and serviceable. Maintenance work includes CAPEX activity (for example renewal), although there is a tendency for the term to be more closely associated with OPEX (for example fixing defects like potholes).

Managed stations

Stations that are owned and managed by Network Rail. See Network Rail's website.

MC3 frog & switch grinder

Equipment that grinds frogs, switch points, and stock rails. The pivoting grinding assembly permits alignment of the grindstone parallel to stock rail for full grindstone to rail contact. A flexshaft can be connected for use of hand tools from the MC-3’s power supply. Optional set-off wheel is available.


Mobile Electrical Network Tester and Observation Recorder - A special vehicle that monitors the overhead lines.


Management of Health and Safety at Work Regulations.


Management incentive plan.


Midland Main Line – the railway line between London St Pancras and Sheffield.

Mobile maintenance train (MMT)

Based at locations around the country, MMTs provide a ‘workshop on wheels’ for engineers and track workers as they carry out repairs, renewals and upgrades to the rail network.


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National Highways

The government-owned company with responsibility for operating, maintaining and enhancing the strategic road network. From April 2015 to August 2021, it was known as Highways England. 

Nationally Significant Infrastructure Projects (NSIPs)

 Large scale projects that require a type of planning approval known as ‘development consent’. Section 22 of the Planning Act 2008 sets out the parameters for highways schemes counted as NSIPs.


National Examination Board in Occupational Safety and Health.

Negative short circuiting devices

A device which bonds the conductor rail to the negative return circuit in order to allow a safe isolation.

Network business

Network business means:

  1. the business of providing and operating the licence holder's network, including the maintenance, renewal, replacement, improvement, enhancement and development of the network;
  2. any ancillary service related to the business and activities in paragraph (i);
    and, without limitation, includes:
    1. the purpose of financing the business in paragraph (i) and the services in paragraph (ii); and
    2. any payment or transaction lawfully made or undertaken by the licence holder for a purpose within conditions 4.13(b)(i) to (vii).

Network Code

The Network Code is a common set of rules and industry procedures that apply to all parties who have a contractual right of access to the track owned and operated by Network Rail.

Network services

"Network services" are defined in sections 82(1), (2) and (3), Railways Act 1993 as:"any service which consists of, or is comprised in, the provision or operation of a network (or of any of the track or other installations comprised in a network), but does not include:

  1. services for the carriage of passengers by railway;
  2. services for the carriage of goods by railway;(c) light maintenance services; or
  3. station services."The statute continues by explaining that "network services" includes services of any of the following descriptions:
    1. the construction, maintenance, re-alignment, re-configuration or renewal of track,
    2. the installation, operation, maintenance or renewal of a railway signalling system or of any other railway communication equipment,
    3. the construction, control, maintenance or renewal of electrical conductor rails or overhead lines, of any supports for such rails or lines, and of any electrical substations or power connections used or to be used in connection therewith, and the provision of electrical power by means thereof,(d) the provision and operation of services for the recovery or repair of locomotives or other rolling stock in connection with any accident, malfunction or mechanical or electrical failure,
    4. the provision and operation of services for keeping track free from, or serviceable notwithstanding, obstruction (whether by snow, ice, water, fallen leaves or any other natural or artificial obstacle or hindrance) or for removing any such obstruction,
    5. the provision, operation, maintenance and renewal of any plant, equipment or machinery used in carrying on any of the activities specified in paragraphs (a) to (e) above,(g) the exercise of day to day control over train movements over or along any track comprised in the network,
    6. the preparation of a timetable for the purposes of such control as is referred to in paragraph
    7. above, and it is immaterial ... whether or not the person who provides the service in question also provides or operates a network, or any of the track or other installations comprised in a network, or provides the service on behalf of a person who does so."Section 82(2) explains that, for the purposes of the definition of "network services", where a person permits another to use any land or other property comprised in a network he is to be regarded as providing a service which falls within the meaning of "network services".


National Rail Enquiries: a public information provider from RDG offering advice on timetables, fares and other rail queries.


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Occupational health

Open access

Open access passenger train operators are those who operate services purely on a commercial basis, i.e. not under either a franchise or a concession agreement. These are companies who identify an opportunity to run a service which is not currently being provided, and they apply to the Office of Rail and Road (ORR) for the necessary track access rights and to Network Rail for train paths in the timetable. Open access passenger operators include Hull Trains and Grand Central.

Open work items

Jobs or work that has been identified but have not yet been completed.


Operating expense: as distinct from CAPEX (capital expenditure), OPEX refers to ongoing costs incurred by Network Rail to maintain the railway infrastructure. Examples of OPEX include routine safety checks on the railway tracks or repairing signalling when it fails.

OPEX [highways]

Operating expense: as distinct from CAPEX (capital expenditure), OPEX refers to ongoing costs incurred by National Highways to maintain and operate the strategic road network. Examples of OPEX include routine safety inspections, the traffic officer service or fixing defects like potholes. Also referred to as ‘Resource Expenditure’.


Offering Rail Better Information Services: an eight year programme by Network Rail with the aim to improve the information they hold about infrastructure, supporting Network Rail's delivery of best practice asset management, consistent with its network licence obligations.


Office of Rail and Road, as of 1 April 2015: the economic regulator of Britain's mainline railway and health and safety regulator on all Britain's railways. It also monitors England's strategic roads network. It was previously the Office of Rail Regulation.

Outturn Expenditure 

Total expenditure on a major enhancement scheme across all road periods, e.g. RP2, RP3 etc.


A bridge crossing over the railway (Network Rail property). This includes bridges for roads, footpaths, services or industrial use.

Overhead Line Equipment (OLE)

An assembly of metal conductor wires, insulating devices and support structures used to bring traction supply current to suitably equipped traction units. The conducting wires are normally strung between masts or poles in some form of catenary arrangement but simple systems may have a single trolley wire.


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Parliamentary Advisory Council for Transport Safety.


An insulating resilient layer of rubber or similar material fitter between a rail and bearer (a wooden or concrete beam used to support the track) or rail and baseplate (a cast or rolled steel support for flat bottom rails).

Passive crossings

A level crossing without any form of active safety control - normally footpath crossings.


The technical term for the road construction, usually using concrete or asphalt, commonly used to refer to the footway.

Performance indicators (PI) 

Indicators that sit below, and give context to, key performance indicators.

Performance specification 

The part of the road investment strategy that sets out the level of performance that National Highways must deliver in the road period.


Public Concern at Work.


Performance Data Accuracy Code: Establishes the standard of recording of the times at which trains arrive at, depart from, or pass specified points, and the difference between those times and the corresponding times published in the Working Timetable.


Private Finance Initiative, a public-private partnership, where private firms are contracted to complete and manage public projects. 

Percentage point

The unit for the arithmetic difference of two percentages.

Performance indicators (PI) 

Indicators which sit below, and give context to, the key performance indicators.

Performance order

Directs a party in breach of contract to do, or refrain from doing, anything that the arbitral tribunal making the order considers just and reasonable in the circumstances.

Performance planning process

Network Rail decides what resources (operational, maintenance, renewals) it needs to put in place in order to deliver the required performance target set by the Government.

Performance specification 

The part of the Road Investment Strategy which sets out the level of performance that National Highways must deliver in the road period.

Performance strategies

Jointly prepared plans agreed between Network Rail and a train operator to improve performance.

Period (railway accounting)

The railway uses 4 weekly accounting periods rather than months. There are 13 periods in a year.

Periodic review


The periodic review 2008 or PR08 was our assessment of the outputs that Network Rail (who manages the rail infrastructure in Great Britain) must deliver, and the levels of access charges paid by train operators for use of the infrastructure. It covers the five years running from April 2009 to March 2014, also known as control period 4 or CP4.


The periodic review 2013 or PR13 is our assessment of what Network Rail must achieve for the next five year period, the money it needs to do so, and the incentives needed to encourage delivery and outperformance for the period from April 2014 to March 2019. This is also known as control period 5 or CP5.


The periodic review 2018 or PR18 is our assessment of what Network Rail must achieve from April 2019 to March 2024. Also known as control period 6 or CP6.


The periodic review 2023 or PR23 is our assessment of what Network Rail must achieve from April 2024 to March 2029. Also known as control period 7 or CP7.

Permitted business

Permitted business means the Network Business and the Permitted Non-Network Business of Network Rail.


Passenger information during disruption – an industry initiative to improve passenger information. It is regulated by ORR via the passenger information licence condition.


The Train Accident Precursor Indicator Model (the PIM) managed by the Rail Safety and Standards Board (RSSB), measures the risk, per million train miles, of a train accident - i.e. collision, derailment, fire or striking a road vehicle on a level crossing. The measure incorporates 82 precursor events in eight groups. Around 65% of the risk arises from events largely under the control or the responsibility of Network Rail, e.g. track geometry, infrastructure failures, environmental factors (flooding, land slips etc.) and level crossing misuse.

The PIM risk indicator was set to a reference value of 100 at the end of March 2002 and the PIM risk indicator provides a measure of the change in risk relative to this level. A reduction in the index is therefore beneficial, denoting a reduction in risk.

Plain line

Track without switches and crossings.

Planning and Delivering Safe Work (PDSW)

PDSW is a wholesale reform of how infrastructure projects are planned and delivered safely and, ultimately, it makes clear who is responsible.


Points are moveable sections of track which enable trains to move between lines. When they fail (points failure) the points cannot be moved and trains are unable to change lines. Technically called switches and crossings.

Possession disruption index (PDI)

'Possession disruption index – passenger' (PDI-P) and 'Possession disruption index – freight (PDI-F)': a graph indicating the level of disruption caused by possessions over a period of time.

Network Rail needs to restrict access to the network to carry out many of its maintenance and renewals activities.

These restrictions of access are referred to as possessions. Possessions are considered to be 'disruptive' if they impact on the running of passenger or freight operators' normal timetabled services. 


Network Rail needs to restrict access to its network to carry out many of its maintenance and renewals activities. These restrictions of access are referred to as possessions.

Possessions returns

The time by which Network Rail has completed its maintenance and renewals activities and train operators can resume their use of the network to operate their services.


Permanent speed restrictions.


Platform-train interface: the gaps both in terms of width and height between a station platform and a train. It also includes risks from electrocution and falls from platforms without trains being present.

Public performance measure (PPM)

The Public Performance Measure (PPM) is the percentage of trains arriving at their final destination within 5 minutes of their scheduled arrival time (within 10 minutes for long distance services).


Provision and Use of Work Equipment Regulations 1992.


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Quantum firm right

A firm right for a train operating company (TOC) to operate a number of slots in the timetable over a given period.


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Regulatory asset base: The Office of Rail and Road's calculation of the value of Network Rail's assets.


Rail Accident Investigation Branch

Rail Delivery Group (RDG)

The Rail Delivery Group brings together the owners of Britain's Train Operating Companies, Freight Operating Companies and Network Rail to provide leadership to Britain's rail industry.

Rail Operating Centres

Centres which will eventually operate the entire rail network across Britain, replacing more than 800 signal boxes and other operational locations currently used to control trains.

Railway facility

Section 83(1) of the Railways Act 1993 defines "railway facility" as follows: "any track, station or light maintenance depot".

Railway Group Standards

Railway Group Standards (RGS) are produced in accordance with the railway group standards code. The purpose of RGS is to facilitate the management and operation of the shared system that is the mainline railway.

Railway services

"Railway services" are defined in section 82(1) of the Railways Act 1993 as "services of any of the following descriptions:

  1. services for the carriage of passengers by railway;
  2. services for the carriage of goods by railway;
  3. light maintenance services;
  4. station services;
  5. network services."

Railway undertaking

In the context of licensing, any private or public undertaking the principal business of which is to provide rail transport services for goods and/or passengers, with a requirement that the undertaking must ensure traction.


Fatigue cracking on a rail caused by rolling contact stresses from passing wheel-sets. There are several types of RCF, the most notable being Gauge corner cracking.


Delays caused to other train services following an incident they were not directly involved in.


Network Rail became reclassified as a central government body for accounting purposes.

Recovery plan

Quantified and robust plan produced by Network Rail to work constructively with the relevant operators (sometimes represented by a recovery board) to reduce delays to freight services or long distance passenger services.

Regional Delivery Partnerships (RDP)

The Regional Delivery Partnerships incentivise suppliers to improve safety and deliver increased value. This approach contains incentives for results, including: shorter and more accurate roadworks; more efficient, local buying; innovation; and increased environmental benefits. The RDP framework is primarily used to action regional enhancement projects.

Regulatory allowance

The expenditure allowed by ORR in calculating the revenue requirement in the access charges review 2003.

Regulatory target

A regulatory target is a target set for Network Rail by ORR at the conclusion of a periodic review. It defines a level of performance, attainment, or progress that Network Rail is funded to achieve at a point in time. ORR sets Network Rail a range of regulatory targets for each year of a control period, including train service performance, PPM and CaSL.

ORR may enforce delivery of regulatory targets through Network Rail's network licence.

Rejected schedules

Timetable proposals made by train operating companies that Network Rail has rejected.

Relay rooms

A building housing safety critical electrical and electronic signalling equipment such as relays that interface with trackside equipment such as points and signals.

Remote disconnection device

This is a device (together with the Signal Controlled Warning System – SCWS) that is part of a wider track worker safety system.


Major capital works or replacement of the network in order to maintain its required capability. These may be required at specific times but are more often carried out according to Network Rail's own timetable.

Renewal [highways]

Renewal or replacement of a whole asset such as road surfacing or a bridge, or part of an asset such as a bridge joint or road markings, in order to maintain its required capability. This may happen due to life-expiry or failure of an asset, or it may be planned to ensure the continued use of a road asset.  


Regulatory impact assessment.


Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 2013.

Rights review meetings

Process whereby Network Rail and freight operators meet every six-months to establish whether the operators continue to have commercial needs for existing rights in accordance with Part J of the Network Code.


Railway Industry Health and Safety Advisory Committee: provides advice to the ORR Board on railway health and safety.

Road investment strategy (RIS) 

This document sets out a long-term vision for England’s motorways and major roads, including a multi-year investment plan for improving the network and high-level objectives. RIS1 refers to the first road period (2015-20), and RIS2 to the second road period (2020-25).


Risk Management Maturity Model: the tool we use to assess an organisation's ability to achieve excellence in controlling health and safety risks.

Road Investment Strategy (RIS) 

This document sets out a long-term vision for England’s motorways and major roads, including a multi-year investment plan for improving the network and high-level objectives. RIS1 refers to the first road period, and RIS2 to the second road period.

Road period (RP) 

The period that the road investment strategy covers. RP1 covered April 2015 to March 2020. RP2 covers April 2020 to March 2025.

Roads reform 

The package of reforms implemented by the Infrastructure Act 2015, which included the creation of the Highways Monitor and National Highways.


Regional Operations Centres, used to manage the safety and flow of traffic using signs, signals and cameras. Used for the management of incidents and despatch of on-road Traffic Officers.


Railways and Other Guided Transport Systems (Safety) Regulations 2006.

Rolling contact fatigue

General term covering all types of damage incurred at the wheel rail interface.


Rolling stock companies. These bodies own most of the rolling stock used on Britain's railways and lease it to train operators.


Road-rail vehicles: vehicles which can operate on rails and conventional roads.


The Rail Safety and Standards Board (RSSB) is an independent, industry-wide body established under the licences of Network Rail and the passenger and freight train operators. RSSB took over from Railway Safety (a subsidiary of Network Rail) principally to run and supervise the system for the establishment, change and abolition of certain mandatory and technical standards for railway assets and railway operations. Its creation was recommended by Lord Cullen's inquiry into the Ladbroke Grove accident.


Route utilisation strategy.


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Safety Management System (SMS)

In essence, it is a formal arrangement for a safer working environment. All operators and dutyholders are now required to have arrangements in place for managing safety risks. A safety management system defines roles and responsibilities, sets arrangements for safety mechanisms, involves workers in the process and ensures continuous improvement.


Safety Management and interoperability thematic Network for railways systems.


Safety management in railways.


Supervisory control and data acquisition.


The removal of material from a bed or bank of a watercourse or material from a beach by current or wave action. This is a particular problem where the removed material was providing support or restraint to a structure such as a bridge pier or retaining wall, ultimately leading to its collapse.

Section managers

A supervisory post responsible for the day to day maintenance of the track within a permanent way section or area or division.

Services for the carriage of passengers by railway

Section 82(2) of the Railways Act 1993 provides that "services for the carriage of passengers by railway" includes services for and in connection with the carriage of luggage, parcels or mail on trains which at the time are available, and primarily intended, for use by passengers; and references to carrying, or to the carriage of, passengers by railway shall be construed accordingly".

Services relating to railways

"Services relating to railways" are defined in section 67(3ZA) of the Railways Act 1993 as:

  1. "railway services;
  2. the provision or maintenance of rolling stock;
  3. the development, maintenance or renewal of a network, station or light maintenance depot; and
  4. the development, provision or maintenance of information systems designed wholly or mainly for facilitating the provision of railway services."


So far as is reasonably practicable.

Signal controlled warning system (SCWS)

A system connected to the signalling that warns track workers of approaching trains.

Signal failure

Where the signalling system fails to work correctly. This includes signal failures, points failures and track circuit failures.

Smart motorways

Smart motorways differ from conventional motorways in that they seek to regulate traffic to smooth its flow, accounting for the effects of congestion. 
There are three types of smart motorway in England:

  • Controlled Motorway (CM) – with three or more lanes, a hard shoulder and variable speed limits; 
  • Dynamic Hard Shoulder Running (DHS) – with variable speed limits and the hard shoulder selectively opened as a running lane during periods when there is a lower speed limit in force, and emergency areas at regular intervals; and 
  • All Lane Running (ALR) – with variable speed limits and the hard shoulder converted to a permanent running lane, and emergency areas at intervals.


Safety management information system: the system managed by RSSB that Britain's mainline railways uses to report safety information.


Safety Management System.


Signal passed at danger: one of the criteria on which the safety of the national rail network is measured. Relates to the occasions where a train passes a signal at which it should have stopped.


Delays resulting from issues with the timetable.

Spending Review 

A governmental process in the United Kingdom carried out by HM Treasury to set/change firm expenditure limits for a future period (normally several years) and, through public service agreements, define the key improvements that the public can expect from these resources.

Spot bids

A request for one or more train paths made by a train operator after the timetable is agreed.


Schedule Performance Index measures the relationship between the actual progress of work to date and planned (or scheduled) progress.


Safety Risk Model: models the long-term risk trends on Britain's mainline railways and is recalibrated periodically to take account of the harm caused by incidents.

Strategic road network (SRN) 

The road network that National Highways is responsible for managing, comprising the motorways and major ‘A’ roads in England.

Stopped vehicle detection (SVD)

Stopped vehicle detection is a system of radar units installed at the side of an all lane running motorway, detecting vehicles that have stopped in fast flowing traffic.

Station dwell times

The additional time a passenger train uses in stopping at a station stop.

Station services

Section 82(2) of the Railways Act 1993 provides that "station services" means any service which consists of, or is comprised in, the provision or operation of a station", and section 82(4) of the Railways Act 1993 provides that "In determining whether any service is a station service, it is immaterial whether or not the person who provides the service also provides or operates a station, or any part of a station, or provides the service on behalf of a person who does so."

Section 82(2) explains that, for the purposes of the definition of "station services", where a person permits another to use any land or other property comprised in a station he is to be regarded as providing a service which falls within the meaning of "station services".


A track machine that automatically lifts and aligns the track by adding ballast to level the track.

Stop short incidents

Incidents where a train stopped short of a platform leading to some train doors not being aligned with the station platform, which poses a risk of passengers using those doors and potentially stepping into a void.

Strategic Road Network (SRN) 

The road network that National Highways is responsible for managing, comprising the motorways and main ‘A’ roads in England.

Structures [highways]

Structures are a type or class of asset on the SRN that include bridges, viaducts, culverts, retaining walls and gantries.


An eighth mile length of track with average alignment or level faults that exceed a maximum level.



Switches and crossings

Track consisting of switches (an assembly of two movable rails – the switch rails) and two fixed rails (the stock rails) and crossings (an assembly that permits the passage of wheel flanges across other rails where tracks intersect.


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The ability of passengers to obtain travel information, make reservations and book tickets in advance is affected by changes to the timetable caused by Network Rail taking possession of lines in order to maintain, renew and enhance the network. Under Condition 2 of its network licence, Network Rail is required to ensure that accurate timetable information is available to train operators at least twelve weeks in advance.


The operation of lifting the track and simultaneously compacting the ballast underneath the sleepers.

Task risk control sheet

A Network Rail document based on infrastructure maintenance tasks that describes the risk associated with the work, the controls for those risks and the person(s) responsible for implementing the controls.

Technology [highways]

Road technology assets include cameras, electronic signs, stopped vehicle detection and weather stations that are used to monitor conditions, control traffic and inform users on the SRN.


Transport for London.


Where a delayed train service of one train operator delays those of another train operator.


Train operating companies: run the (passenger and freight) trains and services on the network. The representative body for the passenger operating companies is the Rail Delivery Group (RDG).


Total operations processing system. Computer based system used to record information from train describers, signal boxes, and track circuits at junctions. It provided a comprehensive system for monitoring a train’s complete movement cycle from workshop and maintenance through to service, safety restrictions, train schedules and performance. Is used to monitor railway operations and rolling stock usage and for the management of maintenance. Now described as TRUST.


Train protection and warning system: a system that automatically activates a train's brakes if it passes a signal at danger, or is over-speeding (at selective sites), or to prevent risks of buffer stop collisions.

Track circuit

Track circuits are designed to detect the presence of a train, by use of an electrical circuit which is completed by train wheels and axles.

Track circuit failure

Failure of a track circuit or associated equipment, including axle-counter failures.

Track geometry

The horizontal and vertical alignment of the track.

Track maintenance engineers

The Network Rail manager responsible for the delivery of track maintenance and the line management of the track section managers.

Track twist faults

Where particular misalignments between the heights of rails which can cause the risk of train derailment.

Traffic Officer service

National Highways Traffic Officers patrol the motorway network and manage the network from a series of Regional Control Centres, helping to keep traffic flowing smoothly. They manage and coordinate incidents to reduce the impact of incident-related congestion as well as assisting stranded vehicles and arranging mobile and temporary road closures.

Train Accident Risk

The risk from an accident that has been caused by a train (e.g. derailment of the train).

Train regulation

Decisions about prioritisation of services to achieve optimal overall service recovery.

Traincrew diagrams

The itinerary for any of the driver, guard and/or train manager of a train.

Transforming safety and wellbeing

Network Rails strategy to protect worker safety, with a specific commitment to minimise the number of occasions employees need to be on or near the line at risk of contact with trains.

Transport Focus 

The independent transport user watchdog that represents users of the strategic road network and is responsible for managing surveys of road user satisfaction.


Temporary speed restriction imposed for safety reasons. This can arise from the poor condition of track, structures, earthworks, hot weather effects, or following track relaying until the track bed is stabilised.


A type of Temporary speed restriction that has been imposed specifically due to the poor Condition of track (COT).

Tubular stretcher bar

The function of a stretcher bar is to keep the two rails in a railway switch a defined distance apart at all times and to ensure that both rails move simultaneously as a coupled pair when commanded.

Twist faults

Where particular misalignments between the height and width of opposite rails creates a wobble-effect to a train's stability and hence the risk of train derailment.


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International Association of Public Transport


Bridges that allow passage under the railway.

Use period

A period of time determined by the ORR in relation to the Failure to use mechanism under Part J of the Network Code.

Use quota

A quota determined by the ORR in relation to the Failure to use mechanism under Part J of the Network Code.

User worked crossings

Level crossings that rely on the person(s) using them to follow instructions and to operate it safety.


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Vehicle change

Changes made to the part of a track access contract (Schedule 5) which stipulates which railway vehicles are permitted to be used on the network under Part F of the Network Code.

Vertical profile

The longitudinal vertical profile of the track.


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West Coast Main Line – the railway line between London Euston and Glasgow.


West Coast Route Modernisation.

Wet bed

A section of track where the ballast/sleepers become saturated through water contamination/leakage from either above or underground often resulting in a slight dip or reported "rough rides" in the track as trains pass over.

Whistle board crossings

A white circular sign with a grey edge and black W in the centre that indicates to a train driver that they must sound the horn or whistle. This is often used to provide warning to users of accommodation, footpath and occupation crossings.

Workforce lost time injuries

A measure that combines the number of personal injuries which have resulted in lost time that are reported in Safety Management Information System for all Network Rail staff and contractors working on Network Rail’s managed infrastructure, normalised per one hundred thousand hours worked.

Working timetable

Drawn up by Network Rail showing, every train movement on the network. It shows the times of arrival and departure of trains at origin, destination, every intermediate point and appropriate passing points. It also details all the relevant time allowances.


The activities of the WRISA (Wheel Rail Interface System Authority) are now undertaken by the Vehicle/Track System Interface Committee.


Wrong Side Failures: incidents where for various reasons the railway's safety is compromised in some way.