In many cases congestion may grow and reach road curves or areas of limited visibility. In order to prevent from accidents at the tail, a good practice is to warn road user.
Just place TigerVia or EagleVia at the congestion point, and install a VMS several hundred meters ahead. TigerVia or EagleVia will automatically detect the congestion, and thanks to their wireless modem, will directly trigger the sign. Videos, pictures and congestion times can also be sent to the traffic center thanks to a GPRS connection.