Plans for traffic lights on some freeway on-ramps have not left the drawing board - nearly two years after they were announced by the Barnett Government as a major weapon in the fight against Perth's growing peak-hour congestion woes.
It is despite then transport minister Troy Buswell saying in August last year that planning for the ramps was "well-advanced".
Transport Minister Dean Nalder said yesterday that the WA Government still intended to trial the concept and that "development work is ongoing".
He said Main Roads was investigating concepts like the ramp signals "in order to make best use of the existing road network".
The ongoing delay comes as the International Transport Forum released details of research that showed effective traffic management - that can include traffic signals on on-ramps - can reduce travel times by up to 12 per cent.
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 - as few as one or two at a time - as freeway conditions allow.
The initial Perth trial was planned for southbound traffic on Kwinana Freeway, between Roe Highway and Armadale Road. It was to have been part of a $128.5 million project jointly funded by the Federal and WA governments.
But the Federal Labor government made the funding conditional on WA signing up to the National Heavy Vehicle Regulator.
Mr Nalder said the State Government, with the support of the WA road transport industry, refused to sign up to the regulator.
As a result, the Commonwealth reduced its contribution by half.