Traffic management through CCTV

Melbourne city link project.

Motorists using the Domain and Burnley tunnels will be able to identify the new facility's ability to reduce their commute times. However, they may not be aware of the advanced technology employed to ensure their safety while they drive through the tunnels.

The new tunnel systems incorporate many features to assist in the surveillance and monitoring of traffic whilst in the system. Systems such as electronic overhead warning signs, emergency messages broadcast onto normal radio bands, emergency intercoms, air quality and venting systems and a comprehensive Closed Circuit Television System "CCTV".

The entire City Link system has been designed to provide monitoring and surveillance via an integrated traffic management system that incorporates CCTV as its major component.

Camvex Video Surveillance Systems has, over the last fourteen years, provided CCTV solutions for a broad range of applications and has recently completed a major CCTV system upgrade on the Domain and Burnley tunnel systems.

A design brief was presented to Camvex that required the design and implementation of a comprehensive surveillance system for the tunnels. The prime purpose of the CCTV system upgrade is to provide surveillance, security and incident control throughout the length of each tunnel and automatically report emergency intercom requests from within the tunnel.

Because each tunnel curves and varies in depth, there was difficulty minimizing camera numbers, while at the same time guaranteeing total coverage. Optimum camera locations were also compromised because of limitations within the tunnel due to the "traffic envelope", a space within which there must be no protrusion of equipment.

Along with the coverage requirements, the system had to be capable of automatically panning, tilting, zooming and focusing on each of the internal emergency intercom points. When someone calls the control room, they are not only able to hear the caller, but can also see the caller and their situation.

Once the camera locations were finalised, they had to be integrated into the original, main CCTV control system at the Translink, Operations and Management building, in Balton St.

The complex lighting system in each of the tunnels is an important feature of their effectiveness. Tunnel lighting has been designed to allow the driver's eyes to adjust to the different lighting levels within the tunnel and gradually acclimatize. This has been achieved with the use of sodium vapour "yellow" and mercury vapour "white" lighting at the entry and exit points, and predominantly sodium vapour lighting in the tunnel itself.

Camvex provided example recorded images from each of the camera locations and evaluated a number of colour cameras and lenses to determine the most appropriate camera lens combination for the application.

The lenses had to provide good focus depth over long distances and stable clarity in dramatically different lighting conditions. The Cosmicar H20ZME 12mm-240mm Motorised Zoom Lens was found to be the best performing lens under the conditions. It was able to provide even focus from wide traffic shots through to close ups of the emergency intercom caller.

Low light levels and narrow spectrum lighting challenge CCTV lenses to perform, the challenge is magnified many times when looking for a colour camera to provide the desired colour rendition and clarity.

Having tested a number of brands and models of camera, it was determined that the Sony SSC-DC54AP ExwaveHAD ½" CCD Colour Camera performed best for the conditions.

Each of the manoeuvrable cameras used in the tunnels is housed in a robust, external grade housing and mounted on a variable speed, locking pan tilt head. Great care has been taken with the mounting hardware to ensure a robust and safe environment for the camera and transmission equipment.

All control signals to, and video signals from each camera are transmitted via multi mode and single mode fibre networks. Camvex provided a range of Fibre Options video and data transmitters, receivers and multiplexers. The fibre networks terminate at the Translink, Operations and Management building.

Its bound to make the user of Melbourne's newest road system feel comfortable in the knowledge of the extensive safety features.

Parliament House project.

In March 1999 Camvex installed an extensive CCTV system at The Parliament of Victoria. As a 100% Victorian owned and managed business Camvex was proud to be selected as the provider of Parliament's CCTV.

The challenge for us was to provide the latest CCTV technology ,which included manoeuvrable cameras operating on both fibre optic and wireless transmission equipment, while ensuring heritage building standards were maintained.