The council’s transport managers have floated the idea of a congestion tax as an option, in response to a motion from south ward councillor Alex Antic – which asks for potential policies to improve traffic flow in the CBD – to be considered at a council meeting tomorrow night.

Transport Minister Stephen Mullighan described Antic’s motion as a “political stunt” designed to attack the Government, which had “backfired spectacularly” – adding that the Government was “vehemently opposed to a congestion tax for Adelaide’s CBD”.

The brief staff report (page 175) attached to Antic’s motion nominates congestion charging, as well as improvements to the city ring route, as possible long-term options to reduce congestion in the CBD.

“Examples of long-term strategies to alleviate traffic congestion may include congestion charging and city ring route improvements, such as grade separating key intersections (underpasses) to encourage drivers to use the arterial network, rather than using the city as a through-route,” the report says.

Mullighan demanded Antic “immediately explain why he is behind a push to introduce a congestion tax for Adelaide motorists”.

But Antic’s views on the subject are unknown (he did not respond to phone calls from InDaily this morning) and his motion does not specifically call for a congestion tax; rather, it asks for the council to take immediate steps to improve traffic flow and requests policy options.

Comments from the council’s traffic experts, responding to Antic’s motion, suggest the congestion tax as an option.

Council CEO Mark Goldstone told InDaily this afternoon: “Councillor Antic has not suggested a congestion tax – instead, (the council’s) administration put forward examples of several long-term strategies that have been used both in Australia and overseas to alleviate traffic congestion.”

“This included the use of a congestion charge in some cities.”

Nonetheless, Mullighan told InDaily: “This political stunt about congestion seems to have backfired spectacularly – and shows why delivering better public transport, better roads and better cycling facilities should be a priority rather than his grandstanding”.

“The South Australian Government, like every other South Australian apart from Councillor Antic, is vehemently opposed to a congestion tax for the Adelaide CBD,” Mullighan said.

The congestion tax which could be levied as a toll for entering the CBD, or as a charge, based on kilometres travelled, or the time of day – or some combination of the three.

RAA spokesperson Charles Mountain said a congestion tax could discourage customers from spending money in the city, and infrastructure improvements were a better solution.

“It (a congestion tax) can keep out… the very people we want to enter the city,” said Mountain.

“Would we see more traffic in adjacent council areas or on the inner ring route?

“Generally, as a matter of principle, we wouldn’t support it.”

He argued that upgrades to the O-Bahn, due for completion by the end of the year, plus investments in north-south and east-west city bike routes and potential grade separation projects would encourage people to use alternative transport methods and reduce road congestion.

He said separating trams from motor vehicles by building an underpass (or an overpass) at the city’s southern edge, at the intersection of Greenhill and Peacock roads, would encourage motorists to go around the city rather than through it.

“Our preference would be to see an improvement to the performance of alternative routes (and) completion of the north-south and east-west bicycle routes to give people alternative (transport options),” said Mountain.

He added that the city tramline extension would also encourage people to drive less frequently.

The council staff report features a link to an article, penned by University of Melbourne researchers and published last week, that argues congestion charges are likely to reduce road use during peak times – whereas more common policy approaches like building new roads and establishing toll roads did little to reduce congestion.

According to the researchers, congestion charges were a promising policy solution to peak hour gridlock, and were fairer than the national fuel excise and car registration fees, which imposed a disproportionate burden on poorer motorists.

The pair studied the impact of imposing various charges on 1400 Melbourne drivers, whose cars were fitted with GPS devices, in 2015-2016, noting that on congested roads, reducing traffic volumes by five per cent can increase traffic speeds by 50 per cent.

They found that charges that varied by time of day were most effective at reducing peak hour congestion, and charges based on location were highly effective in discouraging motorists from entering Melbourne’s CBD.

The staff report also says the council could commission a ‘scoping’ study, which would cost about $100,000, to “outline the challenges, opportunities, and scenarios specifically associated with improving traffic flow in the City of Adelaide”.

The $160 million O-Bahn City Access Project will, according to the State Government, remove more than 1000 buses from interacting with other traffic and increase the number of lanes on Hackney Road.

Another Government project, the $238 million Torrens Junction upgrade, has removed the level crossing on Park Terrace.

The council’s director of operations Beth Davidson-Park did not respond to InDaily‘s request for comment; city design and transport strategy manager Daniel Bennett declined to comment.