Communications-based train control


Communications-based train control is a railway signaling system that makes use of the telecommunications between the train and track equipment for the traffic management and infrastructure control. By means of the CBTC systems, the exact position of a train is known more accurately than with the traditional signaling systems. This results in a more efficient and safe way to manage the railway traffic. Metros are able to improve headways while maintaining or even improving safety.
A CBTC system is a "continuous, automatic train control system utilizing high-resolution train location determination, independent from track circuits; continuous, high-capacity, bidirectional train-to-wayside data communications; and trainborne and wayside processors capable of implementing automatic train protection functions, as well as optional automatic train operation and automatic train supervision functions," as defined in the IEEE 1474 standard.

Background and origin

The main objective of CBTC is to increase track capacity by reducing the time interval between trains.
Traditional signalling systems detect trains in discrete sections of the track called 'blocks', each protected by signals that prevent a train entering an occupied block. Since every block is a fixed section of track, these systems are referred to as fixed block systems.
In a moving block CBTC system the protected section for each train is a "block" that moves with and trails behind it, and provides continuous communication of the train's exact position via radio, inductive loop, etc.
, was the first radio-based CBTC system | alt=
As a result, Bombardier opened the world's first radio-based CBTC system at San Francisco airport's automated people mover in February 2003. A few months later, in June 2003, Alstom introduced the railway application of its radio technology on the Singapore North East Line. Previously, CBTC has its former origins in the loop based systems developed by Alcatel SEL for the Bombardier Automated Rapid Transit systems in Canada during the mid-1980s. These systems, which were also referred to as transmission-based train control, made use of inductive loop transmission techniques for track to train communication, introducing an alternative to track circuit based communication. This technology, operating in the 30–60 kHz frequency range to communicate trains and wayside equipment, was widely adopted by the metro operators in spite of some electromagnetic compatibility issues, as well as other installation and maintenance concerns.
As with new application of any technology, some problems arose at the beginning mainly due to compatibility and interoperability aspects. However, there have been relevant improvements since then, and currently the reliability of the radio-based communication systems has grown significantly.
Moreover, it is important to highlight that not all the systems using radio communication technology are considered to be CBTC systems. So, for clarity and to keep in line with the state-of-the-art solutions for operator's requirements, this article only covers the latest moving block principle based CBTC solutions that make use of the radio communications.

Main features

CBTC and moving block

CBTC systems are modern railway signaling systems that can mainly be used in urban railway lines and APMs, although it could also be deployed on commuter lines. For main lines, a similar system might be the European Railway Traffic Management System ERTMS Level 3.
In the modern CBTC systems the trains continuously calculate and communicate their status via radio to the wayside equipment distributed along the line. This status includes, among other parameters, the exact position, speed, travel direction and braking distance. This information allows calculation of the area potentially occupied by the train on the track. It also enables the wayside equipment to define the points on the line that must never be passed by the other trains on the same track. These points are communicated to make the trains automatically and continuously adjust their speed while maintaining the safety and comfort requirements. So, the trains continuously receive information regarding the distance to the preceding train and are then able to adjust their safety distance accordingly.
From the signalling system perspective, the first figure shows the total occupancy of the leading train by including the whole blocks which the train is located on. This is due to the fact that it is impossible for the system to know exactly where the train actually is within these blocks. Therefore, the fixed block system only allows the following train to move up to the last unoccupied block's border.
In a moving block system as shown in the second figure, the train position and its braking curve is continuously calculated by the trains, and then communicated via radio to the wayside equipment. Thus, the wayside equipment is able to establish protected areas, each one called Limit of Movement Authority, up to the nearest obstacle. Movement Authority is the permission for a train to move to a specific location within the constraints of the infrastructure and with supervision of speed. End of Authority is the location to which the train is permitted to proceed and where target speed is equal to zero. End of Movement is the location to which the train is permitted to proceed according to an MA. When transmitting a MA, it is the end of the last section given in the MA.
It is important to mention that the occupancy calculated in these systems must include a safety margin for location uncertainty added to the length of the train. Both of them form what is usually called 'Footprint'. This safety margin depends on the accuracy of the odometry system in the train.
CBTC systems based on moving block allows the reduction of the safety distance between two consecutive trains. This distance is varying according to the continuous updates of the train location and speed, maintaining the safety requirements. This results in a reduced headway between consecutive trains and an increased transport capacity.

Grades of automation

Modern CBTC systems allow different levels of automation or , as defined and classified in the IEC 62290-1. In fact, CBTC is not a synonym for "driverless" or "automated trains" although it is considered as a basic enabler technology for this purpose.
The grades of automation available range from a manual protected operation, GoA 1 to the fully automated operation, GoA 4. Intermediate operation modes comprise semi-automated GoA 2 or driverless GoA 3. The latter operates without a driver in the cabin, but requires an attendant to face degraded modes of operation as well as guide the passengers in the case of emergencies. The higher the GoA, the higher the safety, functionality and performance levels must be.

Main applications

CBTC systems allow optimal use of the railway infrastructure as well as achieving maximum capacity and minimum headway between operating trains, while maintaining the safety requirements. These systems are suitable for the new highly demanding urban lines, but also to be overlaid on existing lines in order to improve their performance.
Of course, in the case of upgrading existing lines the design, installation, test and commissioning stages are much more critical. This is mainly due to the challenge of deploying the overlying system without disrupting the revenue service.

Main benefits

The evolution of the technology and the experience gained in operation over the last 30 years means that modern CBTC systems are more reliable and less prone to failure than older train control systems. CBTC systems normally have less wayside equipment and their diagnostic and monitoring tools have been improved, which makes them easier to implement and, more importantly, easier to maintain.
CBTC technology is evolving, making use of the latest techniques and components to offer more compact systems and simpler architectures. For instance, with the advent of modern electronics it has been possible to build in redundancy so that single failures do not adversely impact operational availability.
Moreover, these systems offer complete flexibility in terms of operational schedules or timetables, enabling urban rail operators to respond to the specific traffic demand more swiftly and efficiently and to solve traffic congestion problems. In fact, automatic operation systems have the potential to significantly reduce the headway and improve the traffic capacity compared to manual driving systems.
Finally, it is important to mention that the CBTC systems have proven to be more energy efficient than traditional manually driven systems. The use of new functionalities, such as automatic driving strategies or a better adaptation of the transport offer to the actual demand, allows significant energy savings reducing the power consumption.

Risks

The primary risk of an electronic train control system is that if the communications link between any of the trains is disrupted then all or part of the system might have to enter a failsafe state until the problem is remedied. Depending on the severity of the communication loss, this state can range from vehicles temporarily reducing speed, coming to a halt or operating in a degraded mode until communications are re-established. If communication outage is permanent some sort of contingency operation must be implemented which may consist of manual operation using absolute block or, in the worst case, the substitution of an alternative form of transportation.
As a result, high availability of CBTC systems is crucial for proper operation, especially if such systems are used to increase transport capacity and reduce headway. System redundancy and recovery mechanisms must then be thoroughly checked to achieve a high robustness in operation.
With the increased availability of the CBTC system, there is also a need for extensive training and periodical refresh of system operators on the recovery procedures. In fact, one of the major system hazards in CBTC systems is the probability of human error and improper application of recovery procedures if the system becomes unavailable.
Communications failures can result from equipment malfunction, electromagnetic interference, weak signal strength or saturation of the communications medium. In this case, an interruption can result in a service brake or emergency brake application as real time situational awareness is a critical safety requirement for CBTC and if these interruptions are frequent enough it could seriously impact service. This is the reason why, historically, CBTC systems first implemented radio communication systems in 2003, when the required technology was mature enough for critical applications.
In systems with poor line of sight or spectrum/bandwidth limitations a larger than anticipated number of transponders may be required to enhance the service. This is usually more of an issue with applying CBTC to existing transit systems in tunnels that were not designed from the outset to support it. An alternate method to improve system availability in tunnels is the use of leaky feeder cable that, while having higher initial costs achieves a more reliable radio link.
With the emerging services over open ISM radio bands and the potential disruption over critical CBTC services, there is an increasing pressure in the international community to reserve a frequency band specifically for radio-based urban rail systems. Such decision would help standardize CBTC systems across the market and ensure availability for those critical systems.
As a CBTC system is required to have high availability and particularly, allow for a graceful degradation, a secondary method of signaling might be provided to ensure some level of non-degraded service upon partial or complete CBTC unavailability. This is particularly relevant for brownfield implementations where the infrastructure design cannot be controlled and coexistence with legacy systems is required, at least, temporarily. For example, the New York City Canarsie Line was outfitted with a backup automatic block signaling system capable of supporting 12 trains per hours, compared with the 26 tph of the CBTC system. Although this is a rather common architecture for resignalling projects, it can negate some of the cost savings of CBTC if applied to new lines. This is still a key point in the CBTC development, since some providers and operators argue that a fully redundant architecture of the CBTC system may however achieve high availability values by itself.
In principle, CBTC systems may be designed with centralized supervision systems in order to improve maintainability and reduce installation costs. If so, there is an increased risk of a single point of failure that could disrupt service over an entire system or line. Fixed block systems usually work with distributed logic that are normally more resistant to such outages. Therefore, a careful analysis of the benefits and risks of a given CBTC architecture must be done during system design.
When CBTC is applied to systems that previously ran under complete human control with operators working on sight it may actually result in a reduction in capacity. This is because CBTC operates with less positional certainty than human sight and also with greater margins for error as worst-case train parameters are applied for the design. For instance, CBTC introduction in Philly's Center City trolley tunnel resulted initially in a marked increase in travel time and corresponding decrease in capacity when compared with the unprotected manual driving. This was the offset to finally eradicate vehicle collisions which on-sight driving cannot avoid and showcases the usual conflicts between operation and safety.

Architecture

The typical architecture of a modern CBTC system comprises the following main subsystems:
  1. Wayside equipment, which includes the interlocking and the subsystems controlling every zone in the line or network. Depending on the suppliers, the architectures may be centralized or distributed. The control of the system is performed from a central command ATS, though local control subsystems may be also included as a fallback.
  2. CBTC onboard equipment, including ATP and ATO subsystems in the vehicles.
  3. Train to wayside communication subsystem, currently based on radio links.
Thus, although a CBTC architecture is always depending on the supplier and its technical approach, the following logical components may be found generally in a typical CBTC architecture:
CBTC technology has been successfully implemented for a variety of applications as shown in the figure below. They range from some implementations with short track, limited numbers of vehicles and few operating modes, to complex overlays on existing railway networks carrying more than a million passengers each day and with more than 100 trains.
Despite the difficulty, the table below tries to summarize and reference the main radio-based CBTC systems deployed around the world as well as those ongoing projects being developed. Besides, the table distinguishes between the implementations performed over existing and operative systems and those undertaken on completely new lines.

List

Location/SystemLinesSupplierSolutionCommissioningkmNo. of trainsType of FieldLevel of AutomationNotes
SkyTrain Expo Line, Millennium Line, Canada Line
Thales
SelTrac
1986
85.4
20
GreenfieldUTO
DetroitDetroit People Mover
Thales
SelTrac
1987
4.7
12
GreenfieldUTO
LondonDocklands Light Railway
Thales
SelTrac
1987
38
149
GreenfieldDTO
San Francisco AirportAirTrain
Bombardier
CITYFLO 650
2003
5
38
GreenfieldUTO
Seattle-Tacoma AirportSatellite Transit System
Bombardier
CITYFLO 650
2003
3
22
BrownfieldUTO
Singapore MRTNorth East Line
Alstom
Urbalis
2003
20
43
GreenfieldUTOwith train attendants who drive trains in the event of a disruption.
Hong Kong MTRWest Rail Line
Thales
SelTrac
2003
35.4
29
GreenfieldSTO
Las VegasMonorail
Thales
SelTrac
2004
6
36
GreenfieldUTO
Wuhan Metro1
Thales
SelTrac
2004
27
32
GreenfieldSTO
Hong Kong MTRTuen Ma Line Phase 1
Thales
SelTrac
2004
11.4
15
GreenfieldSTO
Dallas-Fort Worth AirportDFW Skylink
Bombardier
CITYFLO 650
2005
10
64
GreenfieldUTO
Hong Kong MTRDisneyland Resort Line
Thales
SelTrac
2005
3
3
GreenfieldUTO
Lausanne MetroM2
Alstom
Urbalis
2008
6
17
GreenfieldUTO
London Heathrow AirportHeathrow APM
Bombardier
CITYFLO 650
2008
1
9
GreenfieldUTO
Madrid Metro1, 6
Bombardier
CITYFLO 650
2008
48
143
BrownfieldSTO
McCarran AirportMcCarran Airport APM
Bombardier
CITYFLO 650
2008
2
10
BrownfieldUTO
BTS SkytrainSilom Line, Sukhumvit Line '
Bombardier
CITYFLO 450
2009
16.7
47
Brownfield
Greenfield
STOwith train attendants who drive trains in the event of a disruption. These train attendants are on standby in the train.
Barcelona Metro9, 11
Siemens
Trainguard MT CBTC
2009
46
50
GreenfieldUTO
Beijing Subway4
Thales
SelTrac
2009
29
40
GreenfieldSTO
New York City SubwayBMT Canarsie Line
Siemens
Trainguard MT CBTC
2009
17
69
BrownfieldSTO
Shanghai Metro6, 7, 8, 9, 11
Thales
SelTrac
2009
238
267
Greenfield and BrownfieldSTO
Singapore MRTCircle Line
Alstom
Urbalis
2009
35
64
GreenfieldUTOwith train attendants who drive trains in the event of a disruption. These train attendants are also on standby between Botanic Gardens and Caldecott stations.
Taipei MetroNeihu-Mucha
Bombardier
CITYFLO 650
2009
26
76
Greenfield and BrownfieldUTO
Washington-Dulles AirportDulles APM
Thales
SelTrac
2009
8
29
GreenfieldUTO
Beijing SubwayDaxing Line
Thales
SelTrac
2010
22
GreenfieldSTO
Beijing Subway15
Nippon Signal
SPARCS
2010
41.4
28
GreenfieldATO
Guangzhou MetroZhujiang New Town APM
Bombardier
CITYFLO 650
2010
4
19
GreenfieldDTO
Guangzhou Metro3
Thales
SelTrac
2010
67
40
GreenfieldDTO
London UndergroundJubilee line
Thales
SelTrac
2010
37
63
BrownfieldSTO
London Gatwick AirportShuttle Transit APM
Bombardier
CITYFLO 650
2010
1
6
BrownfieldUTO
Milan Metro1
Alstom
Urbalis
2010
27
68
BrownfieldSTO
Philadelphia SEPTASEPTA Light Rail Green Line
Bombardier
CITYFLO 650
2010
8
115
STO
Shenyang Metro1
Ansaldo STS
CBTC
2010
27
23
GreenfieldSTO
B&G MetroBusan-Gimhae Light Rail Transit
Thales
SelTrac
2011
23.5
25
GreenfieldUTO
BTS SkytrainSukhumvit Line '
Bombardier
CITYFLO 450
2011
14.35
Brownfield
Greenfield
STOwith train attendants who drive trains in the event of a disruption. These train attendants are on standby in the train.
Dubai MetroRed, Green
Thales
SelTrac
2011
70
85
GreenfieldUTO
Madrid Metro
Invensys
Sirius
2011
9
?
BrownfieldSTO
Paris Métro
Siemens
Trainguard MT CBTC
2011
16
53
BrownfieldDTO
Sacramento International AirportSacramento APM
Bombardier
CITYFLO 650
2011
1
2
GreenfieldUTO
Shenzhen Metro3
Bombardier
CITYFLO 650
2011
42
43
STO
Shenzhen Metro2, 5
Alstom
Urbalis
2010 - 2011
76
65
GreenfieldSTO
Shenyang Metro2
Ansaldo STS
CBTC
2011
21.5
20
GreenfieldSTO
Xian Metro2
Ansaldo STS
CBTC
2011
26.6
22
GreenfieldSTO
YonginEverLine
Bombardier
CITYFLO 650
2011
19
30
UTO
Algiers Metro1
Siemens
Trainguard MT CBTC
2012
9
14
GreenfieldSTO
Chongqing Metro1, 6
Siemens
Trainguard MT CBTC
2011 - 2012
94
80
GreenfieldSTO
Guangzhou Metro6
Alstom
Urbalis
2012
24
27
GreenfieldATO
Istanbul MetroM4
Thales
SelTrac
2012
21.7
Greenfield
Istanbul MetroM5BombardierCityFLO 650Phase 1: 2017
Phase 2: 2018
16.921GreenfieldUTO
Ankara MetroM1Ansaldo STSCBTC201814.6BrownfieldSTO
Ankara MetroM2Ansaldo STSCBTC201416.5GreenfieldSTO
Ankara MetroM3Ansaldo STSCBTC201415.5GreenfieldSTO
Ankara MetroM4Ansaldo STSCBTC20179.2GreenfieldSTO
Mexico City Metro12
Alstom
Urbalis
2012
25
30
GreenfieldSTO
New York City SubwayIND Culver Line
Thales & Siemens
Various
2012
GreenfieldA test track was retrofitted in 2012; the line's other tracks will be retrofitted by the early 2020s.
Phoenix Sky Harbor AirportPHX Sky Train
Bombardier
CITYFLO 650
2012
3
18
GreenfieldUTO
Riyadh
Bombardier
CITYFLO 650
2012
4
12
GreenfieldUTO
Metro Santiago1
Alstom
Urbalis
2012
20
42
Greenfield and BrownfieldDTO
São Paulo Commuter Lines8, 10, 11
Invensys
Sirius
2012
107
136
BrownfieldUTO
São Paulo Metro1, 2, 3
Alstom
Urbalis
2012
62
142
Greenfield and BrownfieldUTOOnly line 2 is in operation with CBTC
Tianjin Metro2, 3
Bombardier
CITYFLO 650
2012
52
40
STO
Beijing Subway8, 10
Siemens
Trainguard MT CBTC
2013
84
150
STO
Caracas Metro1
Invensys
Sirius
2013
21
48
Brownfield
Kunming Metro1, 2
Alstom
Urbalis
2013
42
38
GreenfieldATO
Málaga Metro1, 2
Alstom
Urbalis
2013
17
15
GreenfieldATO
Paris Métro3, 5
Ansaldo STS / Siemens
Inside RATP's
Ouragan project
2010, 2013
26
40
BrownfieldSTO
Paris Métro13
Thales
SelTrac
2013
23
66
BrownfieldSTO
Toronto subway1
Alstom
Urbalis
2017 to 2022
21.6
65
Brownfield
Greenfield
STOCBTC active between St Patrick and Vaughan Metropolitan Centre stations as of May 2019. The entire line is scheduled to be fully upgraded by 2022.
Wuhan Metro2, 4
Alstom
Urbalis
2013
60
45
GreenfieldSTO
Budapest MetroM2, M4
Siemens
Trainguard MT CBTC
2013
2014
17
41
Line M2: STO
Line M4: UTO
Dubai MetroAl Sufouh LRT
Alstom
Urbalis
2014
10
11
GreenfieldSTO
Edmonton Light Rail TransitCapital Line, Metro Line
Thales
SelTrac
2014
24 double track
94
BrownfieldDTO
Helsinki Metro1
Siemens
Trainguard MT CBTC
2014
35
?
Greenfield and BrownfieldSTO
Hong Kong MTRCHong Kong APM
Thales
SelTrac
2014
4
14
BrownfieldUTO
Incheon Subway2
Thales
SelTrac
2014
29
37
GreenfieldUTO
Jeddah Airport
Bombardier
CITYFLO 650
2014
2
6
GreenfieldUTO
London UndergroundNorthern line
Thales
SelTrac
2014
58
106
BrownfieldSTO
Massachusetts Bay Transportation AuthorityAshmont–Mattapan High Speed Line
Argenia
SafeNet CBTC
2014
6
12
GreenfieldSTO
Munich AirportMunich Airport T2 APM
Bombardier
CITYFLO 650
2014
1
12
GreenfieldUTO
Nanjing MetroNanjing Airport Rail Link
Thales
SelTrac
2014
36
15
GreenfieldSTO
Shinbundang LineDx Line
Thales
SelTrac
2014
30.5
12
GreenfieldUTO
Ningbo Metro1
Alstom
Urbalis
2014
21
22
GreenfieldATO
Panama Metro1
Alstom
Urbalis
2014
13.7
17
GreenfieldATO
São Paulo Metro15
Bombardier
CITYFLO 650
2014
25
54
GreenfieldUTO
Shenzhen Metro9
Thales Saic Transport
SelTrac
2014
25.38
Greenfield
Xian Metro1
Siemens
Trainguard MT CBTC
2013 - 2014
25.4
80
GreenfieldSTO
Amsterdam MetroL50, L51, L52, L53, L54
Alstom
Urbalis
2015
62
85
Greenfield and BrownfieldSTO
Beijing Subway1, 2, 6, 9, Fangshan Line, Airport Express
Alstom
Urbalis
From 2008 to 2015
159
240
Brownfield and GreenfieldSTO and DTO
BTS SkytrainSukhumvit Line '
Bombardier
CITYFLO 450
2015
1.7
GreenfieldSTOSamrong extension installation.
Chengdu MetroL4, L7
Alstom
Urbalis
2015
22.4
GreenfieldATO
Delhi MetroLine 7
Bombardier
CITYFLO 650
2015
55
Nanjing Metro2, 3, 10, 12
Siemens
Trainguard MT CBTC
From 2010 to 2015
137
140
Greenfield
São Paulo Metro5
Bombardier
CITYFLO 650
2015
20
34
Brownfield & GreenfieldUTO
São Paulo Metro17
Thales
SelTrac
2015
17.7
24
GreenfieldUTOunder construction
Shanghai Metro10, 12, 13, 16
Alstom
Urbalis
From 2010 to 2015
120
152
GreenfieldUTO and STO
Taipei MetroCircular
Ansaldo STS
CBTC
2015
15
17
GreenfieldUTO
Wuxi Metro1, 2
Alstom
Urbalis
2015
58
46
GreenfieldSTO
Bangkok MRTPurple Line
Bombardier
CITYFLO 650
2015
23
21
GreenfieldSTOwith train attendants who drive trains in the event of a disruption. These train attendants are on standby in the train.
Buenos Aires UndergroundH
Siemens
Trainguard MT CBTC
2016
8
20
??
Buenos Aires UndergroundC
Siemens
Trainguard MT CBTC
2016
4.5
18
TBDTBD
Hong Kong MTRSouth Island Line
Alstom
Urbalis
2016
7
10
GreenfieldUTO
Hyderabad Metro RailL1, L2, L3
Thales
SelTrac
2016
72
57
GreenfieldSTO
Kochi MetroL1
Alstom
Urbalis
2016
26
25
GreenfieldATO
New York City SubwayIRT Flushing Line
Thales
SelTrac
2016
17
46
Brownfield and GreenfieldSTO
Kuala Lumpur Metro Ampang Line
Thales
SelTrac
2016
45.1
50
BrownfieldUTO
Kuala Lumpur Metro Kelana Jaya Line
Thales
SelTrac
2016
46.4
76
BrownfieldUTO
Kuala Lumpur Metro Bandar Utama-Klang Line
Thales
SelTrac
2020
36
BrownfieldUTO
Singapore MRTDowntown Line
Invensys
Sirius
2013
42
92
GreenfieldUTOwith train attendants who drive trains in the event of a disruption.
Walt Disney WorldWalt Disney World Monorail System
Thales
SelTrac
2016
22
15
BrownfieldUTO
Klang Valley Metro SBK Line
Bombardier
CITYFLO 650
2017
51
74
GreenfieldUTO
Delhi MetroLIne-8Nippon SignalSPARCS2017GreenfeildUTO
Lille Metro1
Alstom
Urbalis
2017
15
27
BrownfieldUTO
Lucknow MetroL1
Alstom
Urbalis
2017
23
20
GreenfieldATO
New York City SubwayIND Queens Boulevard Line
Siemens/Thales
Trainguard MT CBTC
2017–2022
21.9
309
BrownfieldATOTrain conductors will be located aboard the train because other parts of the routes using the Queens Boulevard Line will not be equipped with CBTC.
Stockholm MetroRed line
Ansaldo STS
CBTC
2017
41
30
BrownfieldSTO->UTO
Taichung MetroGreen
Alstom
Urbalis
2017
18
29
GreenfieldUTO-
Singapore MRTNorth South Line
Thales
SelTrac
2017
45.3
186
BrownfieldUTOwith train attendants who drive trains in the event of a disruption. These train attendants are on standby in the train.
BTS SkytrainSukhumvit Line '
Bombardier
CITYFLO 450
2018
11
GreenfieldSTOSamut Prakarn extension installation.
Singapore MRTEast West Line
Thales
SelTrac
2018
57.2
186
Brownfield
Greenfield
UTOwith train attendants who drive trains in the event of a disruption. These train attendants are on standby in the train.
Copenhagen S-TrainAll lines
Siemens
Trainguard MT CBTC
2021
170
136
BrownfieldSTO
Doha MetroL1
Thales
SelTrac
2018
33
35
GreenfieldATO
New York City SubwayIND Eighth Avenue Line
Siemens/Thales
Trainguard MT CBTC
2018–2024
9.3
BrownfieldATOTrain conductors will be located aboard the train because other parts of the routes using the Eighth Avenue Line will not be equipped with CBTC.
Ottawa Light RailConfederation Line
Thales
SelTrac
2018
12.5
34
GreenfieldSTO
Port Authority Trans-Hudson All lines
Siemens
Trainguard MT CBTC
2018
22.2
50
BrownfieldATO
Siemens
Trainguard MT CBTC
2018
12
19
GreenfieldUTO
Riyadh MetroL4, L5 and L6
Alstom
Urbalis
2018
64
69
GreenfieldATO
Sosawonsi Co. Seohae Line
Siemens
Trainguard MT CBTC
2018
23.3
7
Greenfield
ATO
Bangkok MRTBlue Line
Siemens
Trainguard MT CBTC
2019
47
54
Brownfield & GreenfieldSTOwith train attendants who drive trains in the event of a disruption.
BTS SkytrainSukhumvit Line
Bombardier
CITYFLO 450
2019
17.8
24
GreenfieldSTOPhaholyothin extension installation.
Buenos Aires UndergroundD
TBD
TBD
2019
11
26
TBDTBD
Hong Kong MTREast Rail Line
Siemens
Trainguard MT CBTC
2019
41.5
37
BrownfieldSTO
Panama Metro2
Alstom
Urbalis
2019
21
21
GreenfieldATO
Singapore MRTThomson-East Coast Line
Alstom
Urbalis
2019
43
91
GreenfieldUTO
Sydney MetroMetro North West Line
Alstom
Urbalis
2019
37
22
BrownfieldUTO
GimpoGimpo Goldline
Nippon Signal
SPARCS
2019
23.63
23
GreenfieldUTO
Jakarta MRTNorth-South line
Nippon Signal
SPARCS
2019
20.1
16
GreenfieldSTO
Bangkok MRTPink, Yellow
Bombardier
CITYFLO 650
2020
64.9
72
GreenfieldUTO
Hong Kong MTRKwun Tong Line, Tsuen Wan Line, Island Line, Tung Chung Line, Tseung Kwan O Line, Airport Express
Alstom-Thales
Advanced SelTrac
2020
158
BrownfieldSTO & DTO
Suvarnabhumi Airport APMMNTB to SAT-1
Siemens
Trainguard MT CBTC
2020
1
6
GreenfieldUTO
Klang Valley Metro SSP Line
Bombardier
CITYFLO 650
2021
52.2
GreenfieldUTO
São Paulo MetroLine 6
Nippon Signal
SPARCS
2021
15
24
GreenfieldUTO
London UndergroundMetropolitan, District, Circle, Hammersmith & City
Thales
SelTrac
2021 to 2022
310
192
BrownfieldSTO
Guangzhou MetroLine 4, Line 5
Siemens
Trainguard MT CBTC
?
70
?
Guangzhou MetroLine 9
Thales
SelTrac
2017
20.1
11
GreenfieldDTO
Marmaray LinesCommuter Lines
Invensys
Sirius
?
77
?
GreenfieldSTO
São Paulo Metro4
Siemens
Trainguard MT CBTC
2010
13
29
GreenfieldUTO2 stations under construction
Salvador Metro4
Thales
SelTrac
2014
33
29
GreenfieldDTO
TokyoJōban Line
Thales
SelTrac
-2017
30
70
BrownfieldSTOThe plan was abandoned because of its technical and cost problems; the control system was replaced by.
TokyoTokyo Metro Marunouchi Line
Mitsubishi
?
2023
27.4
53
Brownfield?
TokyoTokyo Metro Hibiya Line
?
?
2023
20.3
42
Brownfield?
JR WestWakayama Line
?
?
2023
42.5
?
Brownfield?
Baselland Transport Line 19 Waldenburgerbahn
Stadler
CBTC
2022
13.2
10
GreenfieldSTO
AhmedabadMEGANippon SignalSPARCS?39.25996 coaches---