That’s according to the results of RAA’s latest travel time survey, which shows the Glenelg tram is a major contributor to crawling traffic on three key Adelaide roads.

In particular, the triangle of Marion Rd, Anzac Hwy and Cross Rd has been identified as one of the slowest spots across the road network.

RAA Senior Manager of Road Safety, Charles Mountain, said members had made it clear they were frustrated with bottlenecks caused by passing trams, and – looking at the data – it’s not hard to see why.

On Marion Rd, average speeds dropped as low as 7km/h at 7.50am.

“Having three major intersections so close to one another is bound to lead to congestion, but this is compounded by the tramline that bisects this triangle of roads,” Mr Mountain says.

“For example, on Marion Rd, traffic comes to a complete halt up to 10 times during the morning peak so trams can pass through.”

While there’s no tram crossing on Anzac Hwy itself, the flow-on effect is significant. In fact, the average morning speed sunk as low as 10km/h on the section between Mornington Ave and Marion Rd – meaning it took up to three-and-a-half minutes to travel less than 700m.

Adding to the problem is the fact traffic volumes on sections of Marion Rd and Anzac Hwy have increased by about 15% in the past five years.

While Mr Mountain made it clear RAA supported Adelaide’s tram network, he said any future tram works needed to better take into account impacts on road traffic.

“The government’s transport plan details the need to expand the tram network to address population growth and encourage public transport use. While this would be positive, their plan doesn’t out outline the effect this will have on motorists or what can be done to mitigate it,” Mr Mountain said.

The most logical solution, he says, would be to build a tram overpass or underpass at these congestion points, similar to the one on South Rd, so that motorists don’t have to wait at tram crossings.

“In the meantime, we would like to see the state Integrated Transport and Land Use Plan updated to recognise the significant congestion that occurs due to vehicles having to wait at tram crossings, so that it can be addressed as part of any future planning for Adelaide’s road network,” he said.