sujet


GOTTHARD TUNNEL, TRAFFIC CONTROL SYSTEM, Switzerland

, 2005 / Extension 2008 / 2010

Challenge

With only one tunnel tube, the Gotthard road tunnel has only one lane per direction and is operated in two way traffic.

The traffic load is very high, with a large number of heavy goods vehicles (HGV). In order to reduce the number of HGV which are in the tunnel at the same time, and to avoid HGV convoys, the access of HGV must be metered.

Details

In order to ensure higher security for the traffic flows, a new evolutionary road control installation allocates the vehicles to the appropriate lanes of the tunnel’s gateway. This gateway can be closed e.g. when the passage of the tunnel is impossible because of an accident.

The systematic metering of vehicles permits only a safe number of vehicles in the tunnel at the same time. By means of a so-called drop control, heavy goods vehicles (HGV) are singularized so that they will not enter the tunnel in large groups. This is especially important in case of fire in order to prevent the spreading of the flames. The necessary signal switchings will be started automatically if there is a fire, if the permitted CO2-concentration is exceeded or if stopped vehicles are detected.

As all the communication faclities have a redundant structure, the system can still be controlled in the event of a defective cable or devices failure.

Extension 2008 / 2010

Besides the implementation of further operating modes, additional metering functions were installed on behalf of ASTRA, the Swiss Federal Roads Office. They are activated in the case of tailbacks on the accessing roads at Naxbergtunnel and Galleria Stalvedro.

The special method of metering automatically adapts to the vehicle volumes inside the Gotthard tunnel. It is used to avoid tailbacks in the areas of those tunnels in front while at the same time keeping enough vehicles in the system so that the maximum capacity of the Gotthard tunnel can be used, if needed. Furthermore, this measure keeps clear the escape routes for emergency vehicles.

During the extension also the so-called emergency control was fundamentally renewed. This allows switching the signal heads (traffic lights) even if the complete network structure fails. The simple pressing of the “immediately“ button allows a quick reaction in stressful emergency situations.

Project Content

  • Central control software
  • 2 Superordinate processor systems with web-server
  • 2 Auxiliary processor systems as emergency control with separate communication and direct access to the road station.
  • 20 Group data processors
  • 82 Sub-stations for the control of approx. 500 signals and traffic lights
  • 52 Measurement cross-sections with induction loops and radar
  • 7 Overheight control installations

Realization

Start of constructions: January 2003.
Begin of operation: September 2005.
Extension: June 2008 – July 2010.

Benefits

  • Establishing homogeneous traffic flow
  • Warning of tailbacks, fire and dangerous traffic conditions
  • Better security management of the traffic flows and fast closure of the tunnel
  • Capacity management / traffic metering

Pictures