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Mar 2007

SoftStop™—A Revolutionary Traffic Control System for Tunnels!


In conjunction with Tunnel Holdings Pty Ltd (owner and operator of Sydney Harbour Tunnel), Laservision has successfully developed and installed a radical new safety warning system that solves the persistent problem of drivers ignoring other more conventional signals to stop. The Laservision system creates the illusion of a solid surface that instantly blocks both southbound lanes which makes the message impossible to miss.

Softstop Barrier System, Water Screens, Traffic Tunnel Safety - Laservision

Passing under Sydney harbour between the Harbour Bridge and the Sydney Opera House, the Sydney Harbour Tunnel was originally built to alleviate congestion on the Sydney Harbour Bridge. The tunnel was designed to be strong enough to withstand the impact of earthquakes and sinking ships and averages over 30 million vehicles per year.

Since opening, the tunnel has endured over 10,500 traffic incidents ranging from accidents, breakdowns, fire and the odd beachgoer running out of fuel. Delays and closures prove very costly for the Sydney community as the tunnel is a key access route for the city’s business district and eastern suburbs.

Softstop Barrier System, Waterscreen, Traffic Tunnel Safety - Laservision

Although Softstop gives motorists a confronting message “STOP”, the product does allow for people and emergency teams to pass through without incident…. the product is also forgiving for motorists who cannot stop within the reasonable response time. Once the traffic has been brought to a stand still a 2nd ‘physical barrier’ is utilised. Once initiated the Softstop Barrier System is usually on for approximately 1-2 minutes.

Unlike conventional warning lights, signals or signs that appear in the peripheral vision of drivers, the Softstop® Barrier System is the only visual messaging system that appears in the direct view of drivers (making it impossible to miss).

General Manager of Sydney Harbour Tunnel, Mr Bob Allen stated, “as a tunnel operator I need to be able to stop vehicles entering into the tunnel” . . . “we realised that traditional signage wasn’t enough after the reality check of a fire incident and the impact of several high trucks.”

The following key objectives became apparent for sourcing the Softstop® solution;
1) Safety, (prevention of vehicles entering a dangerous environment), and
2) Infrastructure protection

Softstop Barrier System, Waterscreens, Traffic Tunnel Safety - Laservision

Extreme examples of tunnel disasters include Mont Blanc (France) which claimed 39 lives and burnt for 52 hours. A year later 12 people perished in the Tauern Tunnel (Austria) and the Gotthard Tunnel (Europe) which claimed 11 lives. When a fire breaks out in a tunnel, vehicle occupants are not spectators to an accident, they are potential participants in a disaster.

Besides the human toll, these disasters cause severe damage to infrastructure. Freight routes and even entire economies suffer as a result.

Softstop Barrier System, Water Screen, Traffic Tunnel Safety - Laservision

Softstop’s Research & Development:

The Softstop solution was developed from Laservision’s Government endorsed Research & Development laboratories. Leading projection technologies were trialled in the project’s research phase. Air, water pressures and a myriad of other issues were addressed in both day and night time scenarios. This testing was then followed by a week-long trial onsite.

Softstop Barrier System, Water Screens, Traffic Tunnel Safety - Laservision

The Research and Development phase included the following elements;

  • A specialist hydraulic mix from our considerable experience in water screens spanning 3 decades of hydraulic engineering solutions,
  • Technical obstacles included but not limited to: correct air mix ratio on a variable basis,
  • Critical pressure levels to drive against distortion from wind currents,
  • Rapid start techniques ie less than 3 seconds,
  • Hydraulic efficiencies in terms of flow rates and demand and catch supplies technologies.
  • Recycled or limited waste techniques for resource sensitive environments,
  • Critical screen thickness for effective projection avoiding parallax error distortion,
  • Rapid response interlocked projection technologies to compete with opaque surface and daytime usage,
  • Integration technologies to interlock with other safety devices,
  • Monitor loopbacks of key data areas to monitor.

Additionally, a myriad of other failsafe and pre-emptive strategies make ‘ Softstop ’ a highly effective rapid response barrier system. Laservision’s Director of Design commented that “as impressive as the Sydney Harbour Tunnel structure is, it’s rewarding that our design and R&D teams are able to engineer solutions that will assist in reducing the risk of dangerous events.”

Softstop Barrier System, Waterscreen, Traffic Tunnel Safety - Laservision

While the Sydney Harbour Tunnel hasn’t endured a ‘major disaster’, precautions such as the Softstop barrier system are considered by the tunnel’s operator to be a key response mitigation strategy. Mr Bob Allen commented “we average around 30 collisions a year inside Sydney Harbour Tunnel. By far the biggest cost of these is to the community.”

Mr Bob Allen commented that in one incident, “ we had a fire in the tunnel, motorists ignored the warning lights and signs and continued driving towards the fire. These drivers exposed themselves to smoke and toxic fumes from the fire and then to compound the situation they turned around (in a one-way tunnel) and drove back out of the tunnel against incoming traffic.” He further stated, “this fire was the catalyst for engaging Laservision to develop the solution”.

In another example from Sydney Harbour Tunnel, Mr Bob Allen remarked that “ if we had Softstop at the time and we had been able to stop that truck before it hit the portal, the incident could have been all over within 10 minutes instead of 2 hours. Softstop would have made a huge saving to the community. ”

During peak times, over 12,000 vehicles are inconvenienced by these incidents hourly. 4,000 cars an hour are directed away from the tunnel to join the already congested Sydney Harbour Bridge route.

Mr Bob Allen believes the Softstop innovation can be utilised across many other applications including underground car parks, buildings, ski tubes and mines… He suggested the product will be suitable in “ any application where there is a need to prevent vehicles or even people going into a hostile environment, including accidents, fire or the threat of toxic fumes. ”

Laservision is a world-renowned pioneer of creative, high impact solutions for the attractions, architectural lighting, emergency response, advertising and special events industries. Our creations are projected to targeted, large scale audiences, where the audience becomes an integral part of the experience.

These creations include permanently installed entertainment/communication for theme parks, tourist attractions and other special venues. Laservision also caters for themed celebrations and presentations for both the private and corporate sectors. Laservision’s world-renowned installations include Hong Kong, Singapore, Korea and Sydney’s Darling Harbour.

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