When McLaren Vale was established in the 19th century, the district’s roads and land parcels were set up like a grid – making it easier to get around, but also creating lots of 4-way junctions.
The risks of these junctions came to a head in 2021, when a series of fatal and serious crashes on McLaren Vale’s roads prompted the City of Onkaparinga to undertake a full intersection audit, with the state government then committing $4.2 million for upgrades, supported by Leon Bignell MP.
The council also secured another $737,500 from the federal government’s Black Spot program for the teardrop intersection upgrade at Main Rd and McMurtrie Intersection.
The 21 intersection upgrades, included a compact roundabout, raised ‘rumble strips’, teardrop-shaped islands and high-tech digital warning signs (also known as RJAWS or rural junction active warning systems).
The most significant upgrade – a ‘compact roundabout’ – was completed last year at the junction of Chalk Hill Road, Olivers Road and Field Street (pictured), which was the intersection with the highest number of crashes from 2016–20.
Both the compact roundabout and the high-tech digital warnings signs were innovative solutions, with the roundabout being the first of its kind in SA, and McLaren Vale being the first location in SA where multiple high-tech digital warning signs had been rolled out in one place.
Matt Buckell, the council’s Acting Director of Operations, says it’s a prime example of how the City of Onkaparinga uses data, available funding and a range of different solutions to make the region’s roads safer.
“Our 2021 intersection audit revealed where the safety hotspots were and allowed us to prioritise those with an elevated risk of crashes and associated road trauma,” he says.
“We then used that data to advocate for state and federal government funding and then work with the Department for Infrastructure and Transport to determine the best way to make those intersections safer.”
Matt says data was also at the core of another recent road safety project that saw speed limit reductions on 8 Onkaparinga Hills roads in late 2023.
“Residents had reported concerns about speeding and crashes on those roads for a few years, and our review found that on many of the roads, the average speed of vehicles was lower – sometimes substantially – than the existing speed limit,” Matt explains.
“Speed limit reductions aren’t always popular, but research shows even small decreases in speed leads to significant reductions in crashes and trauma. The decision was made to lower the speed limits in this case as it will have minimal impact on travel times while enhancing road safety.”
A study of travel speeds on the Onkaparinga Hills roads in the 9 months after the reductions came into effect indicated – using a respected international speed model – that the risk of fatal crashes had been reduced by 36 per cent, while the risk of serious injury crashes had been reduced by 28.6 per cent.
“It’s worth remembering that speed limits for many roads were set historically, before we fully understood the relationship between speed, crash likelihood and severity,” Matt adds.
“The reviews and audits we undertake help us evolve our approach and ensure that our roads are safe and fit for purpose.”
The correlation between lower speeds and reduced road trauma is the reason 3 of the council’s upcoming road safety projects feature schools.
Two of them – a traffic calming scheme at Flagstaff Hill’s Craigburn Primary School ($154,500) and school crossing at Morphett Vale’s Antonio Catholic School ($100,700) – are funded through the federal government’s Black Spot program; while the council is funding a new koala crossing at Morphett Vale’s Southern Vales Christian College.
The City of Onkaparinga maintains a $1.2 billion road network including 1,384km of sealed roads, 137km of unsealed roads, 45km dust sealed roads, and more than 30km of guard rails.
Matt says the sheer size of this network means the council can’t solve every issue overnight.
“But by seeking and reviewing the data, securing funding and being prepared to use a range of different solutions, we’re committed to making Onkaparinga’s roads safer.”