User:BlueBlackShirt/sandbox

Auckland has currently 84 ramp meters across the Southern, South Western, Northern and North Western motorways making it the largest Southern Hemisphere ramp metering system. Ramp metering was installed Auckland-wide after a successful trial on Mahunga Drive in 2004, before the Mangere Bridge.

Traffic data collected from 25 ramp metering sites in 2007 (before ramp metering deployment) and 2009 (after) shows an average 25% improvement in both congestion duration and traffic speed as well as an 8% increase in traffic throughput. The data also shows an average reduction in crashes of 22%.

The system controlling the ramps promotes the traditional coordination among on-ramps as well as real-time integration with traffic signals on the adjacent arterial network allowing the whole traffic network to be managed as a single integrated road network. For example, when motorway incidents adversely impact the adjacent arterial roads, an automatic response to the arterial traffic signals can be triggered to mitigate the impacts of the incident and vice-versa. Recurrent and excessive traffic queues at on-ramp and off-ramp can also be managed in an integrated way in real-time. This integrated management is possible in Auckland because the same adaptive SCATS system controls both arterial traffic lights and motorway ramp meters.