Stand-off stalls freeway traffic trial
New modelling has shown that "ramp metering" - where freeway flow is controlled by traffic signals on freeway on-ramps - can ease congestion, increase travel time reliability and cut fuel use.
But its trial introduction on Perth freeways is bogged down by a funding stand-off between the State and Federal governments.
Introducing ramp signals - known as managed motorways in some countries - is part of a $128.5 million project that the Federal and State governments were to jointly fund.
Widely used in North America, Europe and Japan, ramp signals are activated during peak periods to control the flow of traffic entering a freeway.
They are installed well down from the ramp entrance to allow the ramps to be used as "temporary storage" for excess vehicles.
Vehicles are released - perhaps as few as one or two at a time - as freeway conditions allow.
At an Australian Institute of Traffic Planning and Management conference yesterday, transport planner Miaad Khayatian said modelling had been done to measure the impact of ramp metering on a section of the Mitchell Freeway.
Without the metering, a 900m queue - equal to about 250 vehicles - developed north of Hepburn Avenue. A queue did not form with ramp metering.
The number of times vehicles had to stop fell about 40 per cent.
State Transport Minister Troy Buswell said planning for the ramp signals - and other initiatives including new message signs and more CCTV cameras - was well-advanced.
He said talks with the Federal Government were continuing.
