ISO/TR 18155:2025
(Main)Railway applications — Principles of train detection for operations and services
Railway applications — Principles of train detection for operations and services
This document describes the general principles of train detection for operations and services which are applied to any railway. This document provides the link of train detection with management of operational principles. It includes descriptions of operational and environmental conditions affecting train detection and impacts on operations. This document provides non-technical guidance for supporting the choice of a suitable train detection method relating to railway operations, for new lines and upgrade or renewal of train detection systems. This document excludes all technical aspects.
Applications ferroviaires — Principes de détection des trains pour les opérations et services
General Information
Standards Content (Sample)
Technical
Report
ISO/TR 18155
First edition
Railway applications — Principles
2025-11
of train detection for operations
and services
Applications ferroviaires — Principes de détection des trains pour
les opérations et services
Reference number
© ISO 2025
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ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Operational aspects regarding train detection . 1
4.1 General .1
4.2 Application situation of train detection in operations .2
4.3 Impacts of train detection on operations .2
4.3.1 Impacts of train detection on operation safety .2
4.3.2 Impacts of train detection on operation efficiency .3
4.4 Combined application of train detection methods .3
5 Application of train detection . 3
5.1 General principles of train detection related methods .3
5.1.1 Categorization .3
5.1.2 Operational characteristics .4
5.1.3 Environmental conditions .4
5.1.4 Principles under normal operation .4
5.1.5 Principles under degraded operation .5
5.1.6 Selection principles .5
5.2 Operational and environmental conditions affecting train detection methods .6
5.3 Impact of train detection method on normal and degraded operations .8
5.3.1 Operation management guidance in normal situations .8
5.3.2 Operation management guidance in degraded situations .10
5.4 Possible selection criteria for train detection method .11
5.4.1 Selection criteria .11
5.4.2 Application in practice . 12
Bibliography . 14
iii
Foreword
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This document was prepared by Technical Committee ISO/TC 269, Railway applications, Subcommittee SC 3,
Operations and services.
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iv
Technical Report ISO/TR 18155:2025(en)
Railway applications — Principles of train detection for
operations and services
1 Scope
This document describes the general principles of train detection for operations and services which are
applied to any railway. This document provides the link of train detection with management of operational
principles. It includes descriptions of operational and environmental conditions affecting train detection
and impacts on operations.
This document provides non-technical guidance for supporting the choice of a suitable train detection
method relating to railway operations, for new lines and upgrade or renewal of train detection systems.
This document excludes all technical aspects.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
train detection
safe recognition of the presence or absence of any trains on a defined section of the track or at a given point
[SOURCE: IEC 62290-1:2025, 3.1.41]
4 Operational aspects regarding train detection
4.1 General
The detection of the presence of train contributes to the avoidance of collisions and derailment. Different
methods of train detection will contribute to a different extent. Operation is dependent on the position
information of trains, therefore some means of train detection are used.
Figure 1 outlines the boundaries of train detection for operations and services.
Figure 1 — Boundaries of train detection for operations and services
4.2 Application situation of train detection in operations
Train detection has been commonly applied to most railway lines.
There are various train detection methods, which can be classified into two categories (see 5.1.1):
— signal block detection;
— single point detection.
Different train operators adopt distinct train detection methods and use several train detection methods
in some cases, in order to suit their specific operational characteristics and environmental conditions, and
further meet the operational requirements.
Train detection methods exhibit varying characteristics. Selecting appropriate train detection method is
crucial for ensuring operation safety, enhancing operation efficiency and improving operation service
quality. The selection of train detection method is based on the operational characteristics described in
5.1.2 as well as the environmental conditions specified in 5.1.3.
When a specific method of train detection is applied, the equipment supplier, relevant stakeholders and the
operator can work together to establish the application, maintenance and management rules, so as to ensure
that its functions align with the operation requirements and ensure the operation safety and efficiency
according to the operational requirements. At the same time, the operator can always observe the working
status of the train detection equipment to ensure that the train detection function is normal under the
normal operation mode (see 5.1.4). When the train detection function fails, the operator needs to switch to
the degraded operation mode (see 5.1.5) and take appropriate operation management measures.
4.3 Impacts of train detection on operations
4.3.1 Impacts of train detection on operation safety
Train detection is vital for ensuring the safety of train operations. By detecting train presence and occupancy
on tracks, operators can coordinate signalling systems to maintain safe distances between trains. This helps
prevent collisions between trains, as well as between trains and the infrastructure, which enhances overall
railway safety. The details are as follows.
a) For the management of railway operations, the operator can set up an operation control centre to
manage lines within its jurisdiction. Train detection provides information of train position across the
railway network, through which the operator can manage the specific position of each train to grant
safety movement authorities which maintain a safe distance between trains. In certain cases, these
plans need adjustment based on train location, operation time changes, and the status of trains and
lines, such as due to engineering works, failures or accidents.
b) Train detection can be used by train control system, which ensures the safety of train movement, e.g.
calculation of the safe running interval between trains, protection of level crossing with warning to users.
4.3.2 Impacts of train detection on operation efficiency
Train detection plays an important role in providing services for passengers, freight and other users,
ensuring effective capacity management, improving infrastructure utilization and ensuring operational
efficiency.
a) Through train detection, the operator can accurately track the location of the train and estimate the
arrival and departure time of the train at different locations. This information can be used for effective
train scheduling to ensure the smooth flow of trains. Accurate train detection can authorize the use and
cancellation of routes more quickly, shorten the interval between trains and minimize delays, thereby
allowing trains to operate at appropriate speeds and improve operational efficiency.
b) The train detection information is used in passenger information services to serve passengers with
their current location information and predict the arrival time according to the real-time train position
and schedule; it is provided to the freight owners in order to track the location of the freight during the
journey.
c) Train detection information is used for various purposes such as environmental monitoring, fire
alarm, etc., to improve operational services and emergency response capabilities. For example, in train
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