New York City Subway, United States of America
The American city of New York led the way with mass transit systems, and got its first metro line as long ago as 1904. In 1953, control of the system was assumed by the New York City Transit Authority, which also took over the running of all metropolitan bus services.
In 1965, the New York Metropolitan Transportation Authority was set up, and given responsibility for almost all public transport operations in the metropolitan area. The Authority has five subsidiaries, which control bus, subway, commuter rail and suburban bus systems, as well as seven bridges and two tunnels.
Today, the New York city subway is one of the largest and most complex systems of its kind in the world, operating over 714 track miles, and serving the four boroughs of Manhattan, Queens, Brooklyn and the Bronx.
With daily passengers totalling 3.1 million, the New York City Transit system operates 24 hours per day. It is a massive system by any standards, running 6,500 scheduled trains per day, and serving 468 stations on 25 interconnected lines.
More than 3200 turnstiles on the system's 468 stations have been modernised to allow them to take new magnetic MetroCards, which allow free transfer between the subways and buses.
New benefits for passengers using frequent traveller passes are regularly introduced, the latest being an offer allowing passengers buying passes by post to take 44 journeys for the price of 40. Single journeys cost $1.50.
The latest plans for the system consist of a massive re-equipment project, encompassing rolling stock and signalling and communications equipment, details of which are given below.
The overall cost of this project has been estimated at $9bn.
However, the modernization project has not been without its problems. The new republican state governor took back $200m destined for the modernisation project to help balance the city's overall budget.
This was on top of cuts in the system's annual operating subsidy, which has forced the imposition of substantial cuts in operating costs and fare increases.
The New York City Subway's rolling stock is some of the best-known and most distinctive in the world.
However, in one of the biggest re-equipment projects of its type, the original trains are being replaced by 680 cars, designated R142, and built by Bombardier Transportation in Canada. The metro also has an option for a further 200 vehicles.
Kawasaki of Japan will build a further 400 vehicles, to complete the provision of a new generation of trains.
All track on the New York City Subway consists of sleepers on ballast or concrete beds, with resilient pads.
A number of different types of tunnelling method have been used on the system, including cut and cover, under-river bored tunnel, cast iron with concrete liners, and a small number of concrete horseshoe construction.
The system is electrified at 625v dc, with current supplied through a third rail. New workshops and depots, due for completion in 1999, were also included in the overall modernization programme.
Headways on the busiest routes can be as short as 90 seconds, which makes the monitoring and control of the system's 10,675 signals, 205 substations and 540 peak period service trains a considerable challenge.
In July 1998, New York City Transit placed a massive order with computer monitoring and control equipment supplier Syseca for a new rail control centre believed to be one of the most advanced in the world.
The new control centre and automatic train supervision allows New York City Transit staff to efficiently manage and operate the network's Subdivision A territory.
The control centre, or operating theatre, is approximately the size of half a football field. It includes 55 fully integrated voice and data comunication workstations, with up to four monitors each. An additional 59 remote workstations are provided for field and remote monitoring purposes.
The operating theatre also features 22 large scale projection displays, with a viewing surface of 5 by 150ft, showing an overview of the rail system and other information to control centre staff.
The software at the core of the system is Syseca's Advanced Information Management (AIM) system, which features advanced train monitoring and control capabilities and boasts the flexibility to allow it to be easily adapted to meet New York City Transit's unique requirements.
AIM's main functions include train tracking and identification, computer-aided automatic routing and dispatching, report generation, and on-line documentation functions.
Additionally, AIM features a service strategy function that allows controllers to adjust train headways and automatically implement any changes requested by them.
Nabil Ghaly, NYCT's program manager for signals and systems, said: "The ATS is an important part of NYCT's modernization strategy to improve on-time performance and service for its customers."
Work on a connection between the 63rd Street tunnel terminal at Queensbridge/21st Street and Queen's Plaza was begun in the middle of 1994.
The $612 million project was due for completion by 2001.
Other planned improvements include the refurbishment of 91 stations, the provision of better information and communications systems, in particular between passengers and the police, and centralisation of control on a single command post.