Third arrester bed ruled out as state, federal government announce $200m more for South-Eastern Freeway safety upgrade

As the transport minister announces $200m in new freeway safety funding, he’s revealed why he doesn’t think a third arrester bed will stop runaway trucks.

A third arrester bed won’t stop out-of-control trucks ploughing into traffic at the bottom of the South-Eastern Freeway, the transport minister says, because drivers are unlikely to use it.

Instead, the state government will move traffic lights 40m back up the Cross Rd intersection to stop cars queuing in front of the fountain.

And it would extend the freeway’s ‘Managed Motorway’ system, which allows authorities to detect when trucks lose control and lower speed limits.

Tom Koutsantonis has announced $200m in new funding for the freeway upgrade and the traffic lights change, half from the federal government.

Acting Premier Susan Close, Boothby MP Louise Miller-Frost and SA Transport Minister Tom Koutsantonis. Picture: NewsWire / Roy VanDerVegt

Effectively ruling out a third arrester bed, he said truck drivers were unlikely to use it if it was built.

“We could spend $150m putting in a third arrester bed just to watch rogue drivers drive right past it,” he said. “Or we can actually fix the intersection and put in a managed motorway to clear that intersection.”

There are two arrester beds on the freeway downtrack - one just before the tunnels entry and one at the bottom of the hill. It’s long been argued a third would help prevent catastrophic truck crashes, such one that killed two people in 2014.

Mr Koutsantonis said a managed motorway allowed authorities to identify speeding trucks or those in the wrong gear, change the freeway speed limit and clear the intersection “to make sure cars aren’t queued up there”.

“The idea we could stop every truck coming down the freeway, or that a third arrester bed is going to fix this is folly,” he said.

Traffic lights at the intersection at the bottom of the South-Eastern freeway will be moved about 40m back up Cross Rd to get queuing cars away from potential truck crashes.

Traffic in the Heysen Tunnels on the South-Eastern Freeway. Picture: NewsWire / Roy VanDerVegt

“Now we have resourcing with the Commonwealth, we can get our skates on. There’s going to be service relocation and we will take into account different trajectories of different trucks and different lanes.”

Detailed designs for moving the traffic lights would be finalised by December, but the cost or finish date is unknown. A spokesperson said the government was looking at available technology around traffic light management.

The $200m is on top of $100m for the freeway upgrade in the federal budget, which also reinstated $150m for the Verdun and Mount Barker freeway interchange upgrades.

Mr Koutsantonis also ruled out a Hahndorf link road as called for by residents, saying the cost-benefit ratio “didn’t stack up”.

“For every million dollars we invest in that program, we get $70,000 back, and it would cost over $100m to build,” he said. “The link road doesn’t add up.

“What you’re going to see with the Mount Barker interchange is a lot more people using the actual Hahndorf bypass, which is the South-Eastern Freeway.”

Upgrading the Verdun interchange to finally allow cars to access the freeway and head up the hill will take about 1000 cars from the Hahndorf main street, he said.

“I’m confident this will address the issues, but there are some people who do not want any traffic in Hahndorf. It’s a premier tourist destination and gets a million visitors a year. It’s busy for a reason. I’m not sure I can take every single car out of Hahndorf. It’s just not feasible.

Opposition transport spokesman Vincent Tarzia said the safest option to stop runaway truck crashes included a third arrester bed, and the state government was yet to present an “evidence-based reason” for not doing so.

The Mount Barker interchange upgrade includes a new three-lane bridge over the freeway for northbound traffic, while the existing bridge will be converted to three lanes for southbound traffic.