By using already installed optical fibre, the Distributed Acoustic Sensing (DAS) technology can detect changes in traffic. OptaSense says a single fibre cable can replace hundreds or thousands of traditional single-point sensors, and give the traffic control centre a warning that something is happening.

Distributed Acoustic Sensing (DAS) provides continuous acoustic measurements along the entire length of an optical fibre. System uses dark fibre from a roadside communications network cable. Existing cable deployed in buried ducting in the verge. No roadside equipment installations required, only fibre. By using already laid fibre, ideally on both sides of the highway, new levels of traffic flow monitoring, management incident detection and hard shoulder monitoring are all achievable with this technology. This can be interfaced in real-time to control systems for use in the traffic control centre.

The sensing system will detect when moving traffic comes to a change/stop and can provide an accurate location of the incident. In addition, any associated noise created by an incident in close up to the fibre, is separately detected and will add to the understanding of the severity of the incident.

OptaSense states that traffic is monitored at 10 meter points in real time along the whole length of the deployed roadside fiber. with their system The constant data output can be integrated into a client’s existing command and control systems which in turn instructs their various roadside traffic signage as well as providing the infrastructure operators and maintainers with a set of clear Graphical User Interfaces to allow for effective monitoring and decision making. A client can choose various speed limits that require alerts to be generated.

The sensing system will detect when moving traffic comes to a halt as part of the traffic flow application above and provide an accurate location of the incident. In addition, any associated noise created by an incident in close proximity to the fiber, is separately detected and will add to the understanding of the severity of the incident.

This can be a valuable alternative for detecting incidents when it comes to tunnels.  

Web address: http://www.optasense.com