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Automation will Enhance Quality and Security of Meteor 14th Line of Paris Metro
Copyright © IFAC Transportation Systems Ch ani a, Greece, 1997
AUTOMATION WILL ENHANCE QUALITY AND SECURITY OF METEOR 14TH LINE OF PARIS METRO
by Pierre GRIFFE
RATP Departement des Projets LAC A 67 54, quai de la Rapee 75599 PARIS CEDEX 12
Tel. 01446831 72 Fax 01446831 00
Abstract : RA TP is building Meteor, the 14th line of Paris Metro. Trains will be driven by fully automated systems and will not require RA TP employees on board. This fundamental choice was made for technical, economic and staffing reasons in order to ensure an excellent service. The automatic train control system has been designed to allow a mixed circulation of both automated trains and manually driven trains in order to facilitate the progressive automation of existing conventional metro lines. Safety of the computers used on the system is based on the coded monoprocessor technology. Keywords : Transport, automation, automated guided vehicles, microcomputer based control.
I. MAIN FEATURES OF THE PROJECT
INTRODUCTION RA TP is bringing transport forward into the 21 st century through the construction of its new Metro line METEOR (Metro Est Ouest Rapide) . By the middle of 1998 Meteor will link Madeleine with the left bank development zone via Gare de Lyon and Chatelet.
The Meteor line will be extended from Port de Gennevilliers (in the North) to Orly airport (in the South), covering a distance of some 35 km .
Passengers are becoming increasingly demanding due to the continual improvement in services offered by various other means of transport, including the private cars, High speed trains and air travel. That is why, RA TP has drawn upon the very best of its technical expertise and know-how to design a transport system which will enable it to maintain and expand its market share, meet passenger needs while at the same time remain within its own economic constraints. By means of automation, Meteor will be a metro line offering a whole new concept in quality of travel.
28 stations, including 13 in Paris, are staggered out along the route:
- 8 stations with connections to 11 subway lines ;
- 5 stations with connections express network lines.
1163
to
5 Regional
By no means, is Meteor France's first fully automated metro line. The first rubber-tyred V AL mini-metro line was commissioned in Lille on April 1983 and the same technology was used in Toulouse for its 10 km line A that was inaugurated in 1993. Driverless operation began in Lyon on line D of the Metro on august 1992. Matra transport used its experience on Lyon and Lille's CVAL) networks to develop the Meteor technology. Meteor is distinguished from its predecessors by catering for up to 40,000 passengers/h compared to the 15,000 on Lille's Val. Meteor is also a pilot project for the conversion of the Paris metro network to driverless operation. Consequently Meteor is designed for both driverless and manual operation, the idea being that the automation equipment can be installed by a working crew on a metro line without much disruption. However before converting the Paris Metro network to driverless operation Meteor will have to prove itself in revenue service.
Fig. 1 Meteor's station. Meteor will also stop at two major French railway (SNCF) stations: the Gare de Lyon and Saint-Lazare stations. The first 7 km, underground section in Paris, running from Tolbiac-Massena to Madeleine, will be open to traffic in 1998. The works to extend the line to SaintLazare are scheduled to start in 1998. Eight, 120 m long stations will be able to accommodate trains with 8 cars. The maximum capacity of the line will be 40,000 passengers an hour in each direction with 8 car train set and 85 seconds minimum headway.
The merits of automation: - a high quality of service: - short headways (down to 85 s at peak hours) ; - attractive service at off peak hours thanks to running cost cut ;
First year traffic, conveyed at a commercial speed of 40 km per hour, with a transport capacity of 25 ,000 passengers per hour in both directions, is expected to amount to 60 million trips.
- great regularity (interval management) ; - operational flexibility which allows to adapt the transport offer to uncommon situations without needing extra crews. The transit service offer can be adjusted in real time (within the limit of available trains).
Table 1 Main characteristics of the line Length of stations Maximum capacity Maximum speed Commercial speed Rubber tyred trains number of car motor car trailer car Acceleration Deceleration Width of cars Length of trains
120m 40,000 passengers/h 80 km/h 40 km/h
- high level of safety : - automated safety control systems are more reliable than men. The human error is the cause of the large majority offailures on the metro ;
8 5 3
- platform screen doors. All the stations are equipped with platform screen doors separating the station platform and the track. These platform screen doors will prevent suicides and any unwanted intrusions by people or objects on to the tracks which are currently the major causes of delays on the Paris Metro. Dozens of hours of interruptions per year will thus be saved;
1.25 m/s 2.3 m1s 15 m 120 m
2. TRAINS WITH FULLY AUTOMATIC DRIVING CONTROL
- tele-supervision and intercom link in train and stations with the central control room. - running cost cut.
Trains will be driven by fully automated systems and will not require the presence of RA TP employees on board. This fundamental choice was made for technical, economic and staffmg reasons in order to ensure an improved service quality for passengers in both the short and the long term.
Staff can be efficiently redeployed, getting drivers out of the cab and into the passenger areas restoring customer confidence by offering a feeling of security, better information and assistance, and a friendly "human aspect".
1164
3. THE OPERATING SYSTEM
4. TECHNICAL DETAILS OF METEOR'S AUTOMA TIC TRAIN CONTROL SYSTEM (see Fig. 2 Automatic Train Control System Synoptic)
The chief aim of Meteor is to ensure increased safety for passengers, thus the line will be equipped with highly sophisticated facilities . The system will enable the following : - train routing control, particularly stations;
4.1. Automatic control systems, Signalling In
terminal
The automatic guidance facilities use a multiprocessor computer architecture designed to run with standard VME and the Eurofer norm.
- train movement regulation; - management of stops in stations, as well as the opening and closing of train and platform screen doors ;
Digital wayside-to-train transmission data system is used.
- compliance with signals and control of train speed;
Computers safety is based on the coded monoprocessor technology already implemented on "SACEM", the automatic train protection ATP used on line A of the Paris Regional Express Railway network (RER), and on "Maggaly" the automatic train control system of Lyon's metro D line. The architecture is based on a single microprocessor protected by data coding.
- safe management of electric power supply for traction and the various alarms relative to train movements ; - phonics and visual monitoring of platforms and train interiors by an operator at the Central Control Room (CCR).
The material architecture is distributed among the stations along the line and on board trains. It is also modular to allow easy extensions of lines as well as to allow easy adaptations to existing rolling stocks and networks ... Most facilities are backed-up (doubled), providing a very high availability.
Central control
Line
Station Platform Screen doors
Track Pennonent trcnsmission
Rolling Stock
.....t----===-===-~_~On - board AVE
Fig. 2 Automatic Train Control System Synoptic
1165
5. DESIGN CONSTRAINTS Meteor tracks being connected to an existing metro network, the automated system has to allow for mixed circulation of both A TC-equipped trains and non-equipped ones (manually driven trains) currently in use on the existing network. A second constraint is linked to the yet not decided configuration of the line extensions with a possibility of loops and shunting necks which would enable Meteor's trains to get out of the automated sector and get back to it after having been turned round . The system, therefore, has to record each equipped train it takes charge of when the train enters the automated sector or initiate the trains on board ATC systems.
Fig. 3 Central control room.
4. 2. Central Control Room (CCR)
These two constraints are structuring for the ATe system.
The CCR operators may use all of the facil ities resources allowing them to supervise and regulate train circulation remotely, as well as to control all the essential functions of the network.
5.1. A non-equipped train running among ATCequipped trains
The man-machine interface consists of a LED illuminated diagram panel, computer terminals and control video monitors with a view of platform stations and the inside of trains, including equipment for voice communications with passengers on the platforms and in the trains.
The presence of conventional and thus manually driven trains led to implement a conventional train protection system on Meteor. This system is identical to the metro's : two succeeding trains have a block section (free track circuit block) between them. To minimise the number of track circuits while complying with the contractual headway, a virtual fixed block section has been designed :
A back-up computer, interfaced with the fixed automatic guidance facilities and audio-visual facilities, allows overall management in terms of monitoring train movements, traffic regulation, and automatic stabling and unstabling of trains, according to the timetable.
- Virtual, i.e., the concept is implemented on software ; - Fixed, Le. , although it can be modified, the block layout is pre-determined.
Another computer is in charge of management and aiding systems of ATOS.
From the A TC system's viewpoint, a conventional train shunting a track circuit still occupies all the virtual block sections which overlay this track circuit.
It displays for maintenance operators, via dedicated terminals in the CCR or in the maintenance centres, diagnoses produced by the ATOS "maintenance aiding system", which allow first level standard exchanges.
However and by comparison to a conventional train, an automated train occupies only the set of virtual block sections corresponding to its actual position irrespective of the status of the conventional track circuit.
4.3. A udio-visual facilities Passengers are protected by a dense network of cameras and intercoms in stations and trains, allowing an effective supervision and a direct communication between passengers and the CCR operators. A radiating cable allows transmission inside the tunnel.
5.2. Unpolarised trains A train is polarised if one end of the train always points to the same end of the line. In this case, the direction of the wheel's rotation depends only on the direction of the train's movement. In the case of Meteor, the sense of rotation of the wheels not only depends on the direction of the train's movement, but on the train's polarity as well, which it becomes necessary to determine.
Video images from inside the trains are transmitted by UHF (free propagation) between the trains and the relay-bases on the wayside which send them to the CCR.
1166
It has been decided to record the train's polarity each time:
8. COSTS
- the on board A TC equipment is activated as the train is leaving the stabling track;
The cost of the project for 8 km and 8 stations is around 6,000 million French francs 96 without the rolling stock.
- an automated train is entering the Meteor line. After having been initialised, the polarity is updated in real time as long as the train's A TC system is active - it would never switch off outside the yard.
Table 2 Breakdown of the cost
Land purchase Tunnel civil engineering works Station civil engineering works Line equipment (track, power) Station equipment Electrical an electrical mechanical station equipment Automated train operation system
6. OPERATION AND MAINTENANCE RELATED
CONSTRAINTS If the Meteor project is to be a success the operation and maintenance have to be organised in view of a fully automated system. Train failure recovery modes have to result in the fewest possible manual takeovers. This supposes a wide spread recourse to equipment back-up as well as efficient failuredetecting devices. A Maintenance Support System (MSS) has been designed to that end. In particular, when a back-up equipment breaks down, the maintenance controller must have it replaced by the maintenance team as quickly as possible and before the main equipment, which holds the system fully operational, break down in turn.
2% 33 % 28 % 8% 6% 8% 15 %
Table 3 Breakdown of the cost 900 million French francs 96 for the automated train operation system
System Automatic train control (ATC) Audio-visual facilities Central Control Room (CCR) Platform screen doors Signalling Power control
The MSS has been designed around the concept of Built In Test Equipment (BITE). Each equipment diagnoses itself or is diagnosed by a related equipment. The diagnosis is applied to all first level removal units (FLRU). Examples of such units are electronic drawers, train antennas and odometers. In case of a failure a message is sent to the upper level in charge of synthesising failures in real time and routes results to the Central Maintenance Computer (CMC).
10% 47% 16 %
8% 11 % 7% 1%
Concerning the cost offull automation
The CMC is interfaced with the maintenance controller. The controller is responsible for choosing the proper authority in the matter, such as maintenance station staff or multi-skilled crew. The whole set of data related to the faulty equipment and stored in the CMC's database is made available to the intervention crews. 7. A V AILABILITY A full automated line needs a very high level of safety, reliability and availability. In that field the main targets are: 9
- for each equipment I failure for 10 hours of use ; - 3 untimely emergency brakings per year; - 2 incorrect stoppings (station missed) per year ; - I return to manual driving per year.
1167
Full automation makes it possible to decrease headway between trains and as a result the length of the trains and still provide the same transport capacity. In the same way since trains can be operated without drivers, some trains can be stabled on the line at night during service interruption. Consequently, savings are made on the cost of the stations and on train stabling facilities, particularly when stabling is underground . These savings compensate for the higher cost of full automation . Thus, for the same investment outlay, full automation allows to decrease the operating costs by lowering the number of jobs required tQ operate the line. However this is not Meteor's goal, considering current unemployment and the service quality demands still to be met. The goal is to improve the service quality for the same operating cost. With the same number of people jobs in the commercial field and the maintenance fields can be increased.
CONCLUSION The fully automatic system is today on trial on a 2 km test track in the south of Paris. Since Meteor is due ·to be put in revenue service in mid 1998, the RA TP now has a little less than a one year to show its worth of 40 years experience of continual modernisation of operating methods and improvement in service quality. All of the progresses that have taken place in the past are mostly due to developments in electronics, computer and information technology. If Meteor fulfils its promise these new operating methods should be introduced throughout the metro network. In particular complete automation of the metro network could be achieved at the normal speed of track renewal, i.e. over a period ono to 35 years.
1168
AUTOMATION WILL ENHANCE QUALITY AND SECURITY OF METEOR 14TH LINE OF PARIS METRO
by Pierre GRIFFE
RATP Departement des Projets LAC A 67 54, quai de la Rapee 75599 PARIS CEDEX 12
Tel. 01446831 72 Fax 01446831 00
Abstract : RA TP is building Meteor, the 14th line of Paris Metro. Trains will be driven by fully automated systems and will not require RA TP employees on board. This fundamental choice was made for technical, economic and staffing reasons in order to ensure an excellent service. The automatic train control system has been designed to allow a mixed circulation of both automated trains and manually driven trains in order to facilitate the progressive automation of existing conventional metro lines. Safety of the computers used on the system is based on the coded monoprocessor technology. Keywords : Transport, automation, automated guided vehicles, microcomputer based control.
I. MAIN FEATURES OF THE PROJECT
INTRODUCTION RA TP is bringing transport forward into the 21 st century through the construction of its new Metro line METEOR (Metro Est Ouest Rapide) . By the middle of 1998 Meteor will link Madeleine with the left bank development zone via Gare de Lyon and Chatelet.
The Meteor line will be extended from Port de Gennevilliers (in the North) to Orly airport (in the South), covering a distance of some 35 km .
Passengers are becoming increasingly demanding due to the continual improvement in services offered by various other means of transport, including the private cars, High speed trains and air travel. That is why, RA TP has drawn upon the very best of its technical expertise and know-how to design a transport system which will enable it to maintain and expand its market share, meet passenger needs while at the same time remain within its own economic constraints. By means of automation, Meteor will be a metro line offering a whole new concept in quality of travel.
28 stations, including 13 in Paris, are staggered out along the route:
- 8 stations with connections to 11 subway lines ;
- 5 stations with connections express network lines.
1163
to
5 Regional
By no means, is Meteor France's first fully automated metro line. The first rubber-tyred V AL mini-metro line was commissioned in Lille on April 1983 and the same technology was used in Toulouse for its 10 km line A that was inaugurated in 1993. Driverless operation began in Lyon on line D of the Metro on august 1992. Matra transport used its experience on Lyon and Lille's CVAL) networks to develop the Meteor technology. Meteor is distinguished from its predecessors by catering for up to 40,000 passengers/h compared to the 15,000 on Lille's Val. Meteor is also a pilot project for the conversion of the Paris metro network to driverless operation. Consequently Meteor is designed for both driverless and manual operation, the idea being that the automation equipment can be installed by a working crew on a metro line without much disruption. However before converting the Paris Metro network to driverless operation Meteor will have to prove itself in revenue service.
Fig. 1 Meteor's station. Meteor will also stop at two major French railway (SNCF) stations: the Gare de Lyon and Saint-Lazare stations. The first 7 km, underground section in Paris, running from Tolbiac-Massena to Madeleine, will be open to traffic in 1998. The works to extend the line to SaintLazare are scheduled to start in 1998. Eight, 120 m long stations will be able to accommodate trains with 8 cars. The maximum capacity of the line will be 40,000 passengers an hour in each direction with 8 car train set and 85 seconds minimum headway.
The merits of automation: - a high quality of service: - short headways (down to 85 s at peak hours) ; - attractive service at off peak hours thanks to running cost cut ;
First year traffic, conveyed at a commercial speed of 40 km per hour, with a transport capacity of 25 ,000 passengers per hour in both directions, is expected to amount to 60 million trips.
- great regularity (interval management) ; - operational flexibility which allows to adapt the transport offer to uncommon situations without needing extra crews. The transit service offer can be adjusted in real time (within the limit of available trains).
Table 1 Main characteristics of the line Length of stations Maximum capacity Maximum speed Commercial speed Rubber tyred trains number of car motor car trailer car Acceleration Deceleration Width of cars Length of trains
120m 40,000 passengers/h 80 km/h 40 km/h
- high level of safety : - automated safety control systems are more reliable than men. The human error is the cause of the large majority offailures on the metro ;
8 5 3
- platform screen doors. All the stations are equipped with platform screen doors separating the station platform and the track. These platform screen doors will prevent suicides and any unwanted intrusions by people or objects on to the tracks which are currently the major causes of delays on the Paris Metro. Dozens of hours of interruptions per year will thus be saved;
1.25 m/s 2.3 m1s 15 m 120 m
2. TRAINS WITH FULLY AUTOMATIC DRIVING CONTROL
- tele-supervision and intercom link in train and stations with the central control room. - running cost cut.
Trains will be driven by fully automated systems and will not require the presence of RA TP employees on board. This fundamental choice was made for technical, economic and staffmg reasons in order to ensure an improved service quality for passengers in both the short and the long term.
Staff can be efficiently redeployed, getting drivers out of the cab and into the passenger areas restoring customer confidence by offering a feeling of security, better information and assistance, and a friendly "human aspect".
1164
3. THE OPERATING SYSTEM
4. TECHNICAL DETAILS OF METEOR'S AUTOMA TIC TRAIN CONTROL SYSTEM (see Fig. 2 Automatic Train Control System Synoptic)
The chief aim of Meteor is to ensure increased safety for passengers, thus the line will be equipped with highly sophisticated facilities . The system will enable the following : - train routing control, particularly stations;
4.1. Automatic control systems, Signalling In
terminal
The automatic guidance facilities use a multiprocessor computer architecture designed to run with standard VME and the Eurofer norm.
- train movement regulation; - management of stops in stations, as well as the opening and closing of train and platform screen doors ;
Digital wayside-to-train transmission data system is used.
- compliance with signals and control of train speed;
Computers safety is based on the coded monoprocessor technology already implemented on "SACEM", the automatic train protection ATP used on line A of the Paris Regional Express Railway network (RER), and on "Maggaly" the automatic train control system of Lyon's metro D line. The architecture is based on a single microprocessor protected by data coding.
- safe management of electric power supply for traction and the various alarms relative to train movements ; - phonics and visual monitoring of platforms and train interiors by an operator at the Central Control Room (CCR).
The material architecture is distributed among the stations along the line and on board trains. It is also modular to allow easy extensions of lines as well as to allow easy adaptations to existing rolling stocks and networks ... Most facilities are backed-up (doubled), providing a very high availability.
Central control
Line
Station Platform Screen doors
Track Pennonent trcnsmission
Rolling Stock
.....t----===-===-~_~On - board AVE
Fig. 2 Automatic Train Control System Synoptic
1165
5. DESIGN CONSTRAINTS Meteor tracks being connected to an existing metro network, the automated system has to allow for mixed circulation of both A TC-equipped trains and non-equipped ones (manually driven trains) currently in use on the existing network. A second constraint is linked to the yet not decided configuration of the line extensions with a possibility of loops and shunting necks which would enable Meteor's trains to get out of the automated sector and get back to it after having been turned round . The system, therefore, has to record each equipped train it takes charge of when the train enters the automated sector or initiate the trains on board ATC systems.
Fig. 3 Central control room.
4. 2. Central Control Room (CCR)
These two constraints are structuring for the ATe system.
The CCR operators may use all of the facil ities resources allowing them to supervise and regulate train circulation remotely, as well as to control all the essential functions of the network.
5.1. A non-equipped train running among ATCequipped trains
The man-machine interface consists of a LED illuminated diagram panel, computer terminals and control video monitors with a view of platform stations and the inside of trains, including equipment for voice communications with passengers on the platforms and in the trains.
The presence of conventional and thus manually driven trains led to implement a conventional train protection system on Meteor. This system is identical to the metro's : two succeeding trains have a block section (free track circuit block) between them. To minimise the number of track circuits while complying with the contractual headway, a virtual fixed block section has been designed :
A back-up computer, interfaced with the fixed automatic guidance facilities and audio-visual facilities, allows overall management in terms of monitoring train movements, traffic regulation, and automatic stabling and unstabling of trains, according to the timetable.
- Virtual, i.e., the concept is implemented on software ; - Fixed, Le. , although it can be modified, the block layout is pre-determined.
Another computer is in charge of management and aiding systems of ATOS.
From the A TC system's viewpoint, a conventional train shunting a track circuit still occupies all the virtual block sections which overlay this track circuit.
It displays for maintenance operators, via dedicated terminals in the CCR or in the maintenance centres, diagnoses produced by the ATOS "maintenance aiding system", which allow first level standard exchanges.
However and by comparison to a conventional train, an automated train occupies only the set of virtual block sections corresponding to its actual position irrespective of the status of the conventional track circuit.
4.3. A udio-visual facilities Passengers are protected by a dense network of cameras and intercoms in stations and trains, allowing an effective supervision and a direct communication between passengers and the CCR operators. A radiating cable allows transmission inside the tunnel.
5.2. Unpolarised trains A train is polarised if one end of the train always points to the same end of the line. In this case, the direction of the wheel's rotation depends only on the direction of the train's movement. In the case of Meteor, the sense of rotation of the wheels not only depends on the direction of the train's movement, but on the train's polarity as well, which it becomes necessary to determine.
Video images from inside the trains are transmitted by UHF (free propagation) between the trains and the relay-bases on the wayside which send them to the CCR.
1166
It has been decided to record the train's polarity each time:
8. COSTS
- the on board A TC equipment is activated as the train is leaving the stabling track;
The cost of the project for 8 km and 8 stations is around 6,000 million French francs 96 without the rolling stock.
- an automated train is entering the Meteor line. After having been initialised, the polarity is updated in real time as long as the train's A TC system is active - it would never switch off outside the yard.
Table 2 Breakdown of the cost
Land purchase Tunnel civil engineering works Station civil engineering works Line equipment (track, power) Station equipment Electrical an electrical mechanical station equipment Automated train operation system
6. OPERATION AND MAINTENANCE RELATED
CONSTRAINTS If the Meteor project is to be a success the operation and maintenance have to be organised in view of a fully automated system. Train failure recovery modes have to result in the fewest possible manual takeovers. This supposes a wide spread recourse to equipment back-up as well as efficient failuredetecting devices. A Maintenance Support System (MSS) has been designed to that end. In particular, when a back-up equipment breaks down, the maintenance controller must have it replaced by the maintenance team as quickly as possible and before the main equipment, which holds the system fully operational, break down in turn.
2% 33 % 28 % 8% 6% 8% 15 %
Table 3 Breakdown of the cost 900 million French francs 96 for the automated train operation system
System Automatic train control (ATC) Audio-visual facilities Central Control Room (CCR) Platform screen doors Signalling Power control
The MSS has been designed around the concept of Built In Test Equipment (BITE). Each equipment diagnoses itself or is diagnosed by a related equipment. The diagnosis is applied to all first level removal units (FLRU). Examples of such units are electronic drawers, train antennas and odometers. In case of a failure a message is sent to the upper level in charge of synthesising failures in real time and routes results to the Central Maintenance Computer (CMC).
10% 47% 16 %
8% 11 % 7% 1%
Concerning the cost offull automation
The CMC is interfaced with the maintenance controller. The controller is responsible for choosing the proper authority in the matter, such as maintenance station staff or multi-skilled crew. The whole set of data related to the faulty equipment and stored in the CMC's database is made available to the intervention crews. 7. A V AILABILITY A full automated line needs a very high level of safety, reliability and availability. In that field the main targets are: 9
- for each equipment I failure for 10 hours of use ; - 3 untimely emergency brakings per year; - 2 incorrect stoppings (station missed) per year ; - I return to manual driving per year.
1167
Full automation makes it possible to decrease headway between trains and as a result the length of the trains and still provide the same transport capacity. In the same way since trains can be operated without drivers, some trains can be stabled on the line at night during service interruption. Consequently, savings are made on the cost of the stations and on train stabling facilities, particularly when stabling is underground . These savings compensate for the higher cost of full automation . Thus, for the same investment outlay, full automation allows to decrease the operating costs by lowering the number of jobs required tQ operate the line. However this is not Meteor's goal, considering current unemployment and the service quality demands still to be met. The goal is to improve the service quality for the same operating cost. With the same number of people jobs in the commercial field and the maintenance fields can be increased.
CONCLUSION The fully automatic system is today on trial on a 2 km test track in the south of Paris. Since Meteor is due ·to be put in revenue service in mid 1998, the RA TP now has a little less than a one year to show its worth of 40 years experience of continual modernisation of operating methods and improvement in service quality. All of the progresses that have taken place in the past are mostly due to developments in electronics, computer and information technology. If Meteor fulfils its promise these new operating methods should be introduced throughout the metro network. In particular complete automation of the metro network could be achieved at the normal speed of track renewal, i.e. over a period ono to 35 years.
1168