Véhicule Automatique Léger

VAL-style track point as used on the Taipei Wenhu Line.

The VAL system uses a fully automated elevated guideway, which may be metal or concrete depending on prevailing weather conditions. Primary suspension is by rubber tires, with pairs of horizontal tires to provide lateral guidance. Electrical power at 750 V DC is collected by shoes from the guidebars.[2]

The vehicles are lightweight 2-car sets (VAL 206 or VAL 208) with 124 total capacity, or twin sets (VAL 256) with 80 seated and 160 standing capacity. All axles on these vehicles are motored with 150 kW electrical motors. The system detects the location of trains on the guideway by the use of ultrasonic sensors.[3]

VAL can cope with unanticipated demand by inserting additional trains into the network as required by remote command from the control center. The control center computer system automatically speeds up or slows down trains in order to maintain a timetable. The VAL system can handle headways as small as 60 seconds, and the Lille VAL system rapidly proved itself with a 99.8% availability.[4]

In contrast to another early driverless metro system, the Vancouver SkyTrain, the VAL design uses platforms that are separated from the rollways by a glass partition, to prevent waiting passengers from straying or falling onto the rollways. Platform screen doors – produced by Swiss glass door manufacturer Kaba Gilgen AG – are embedded in these partitions and open in synchrony with the train doors when a train stops at the platform. The original platform-edge doors were manufactured and installed by PLC Peters in Hayes, Middlesex and were used on the first line.

In addition to the trains being driverless, the station platforms are unstaffed in normal operation. In the original Lille metro system, they are monitored by a large closed-circuit television system with 330 cameras and 24 television monitors in a remote control room.[5]

CityVal for Rennes Metro Line B

In 2006 the NeoVal project, successor of the VAL, was announced. It will feature regenerative braking. 40% of the 62 million Euros set aside for the programme will come from the Agence de l'innovation industrielle (the technology-supporting project agency formerly known as the AII). The program is managed by Siemens Mobility, in association with Lohr Industrie. The NeoVal will be guided by a single central rail, similar to that of the Translohr, and will be able to operate without any electrical supply between the stations (no third rail or overhead lines), making the cost of infrastructure much lower.[6]

The NeoVal is offered in two versions:

• the CityVal version designed for conventional transit environments (car width 2.65 m) with the first implementation on Line B of the Rennes Metro;
• the AirVal version designed for airport environments (car width 2.80 m) with the first implementation on the future people mover at Bangkok's Suvarnabhumi Airport.