Project Details
Category Permanent Attractions

SOFTSTOP™ Barrier System, Australia

LocationSydney Harbour Tunnel

SOFTSTOP™ Barrier System

“Activated 8 times in 8 weeks, with 100% success!”
Mr. Bob Allen, General Manager, Tunnel Holdings Pty Ltd (Sydney Harbour Tunnel)

In conjunction with Tunnel Holdings Pty Ltd (owner and operator of Sydney Harbour Tunnel), Laservision has successfully developed and installed a radical new tunnel warning system that solves the persistent problem of drivers ignoring other more conventional signals to stop before entering motorway tunnels. The Laservision system creates the illusion of a solid surface that instantly blocks both southbound lanes of traffic. The Softstop Barrier System produces a pseudo-holographic image that appears to float in mid-air, commanding the attention of the motorist making the ‘STOP’ message impossible to miss. 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.




Passing under Sydney Harbour between the Harbour Bridge and the Opera House, the Sydney Harbour Tunnel was originally built to alleviate congestion on the 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.

General Manager of Tunnel Holding Pty Ltd (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

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’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 nighttime scenarios. This testing was then followed by a week-long trial onsite.

The Research and Development phase included the following elements;

  • A specialist hydraulic mix from our considerable experience in water screens spanning three 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 three 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 fail-safe and pre-emptive strategies make ‘Softstop’ a highly effective, rapid-response barrier system.

While 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 over within 10 minutes instead of two hours. Softstop would have made a huge savings 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.

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 standstill a second ‘physical barrier’ is utilised. Once initiated the ‘Softstop® Barrier System’ is usually on for approximately 1-2 minutes.

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.”