The annual travel time study also showed that congestion is worse during the afternoon peak period than the morning rush.

Across Adelaide, traffic was at its slowest at 5.30pm, when 83 sections of road recorded an average speed of less than 15km/h.

During the morning rush, congestion peaked at 8.30am. At this time, there were 58 sections of road that had an average speed of less than 15km/h.

The dubious distinction of being the slowest spot went to a section of Richmond Rd in the western suburbs.

Motorists heading east on this road between Deacon Ave and South Rd crawled along at an average speed of just 7.8km/h during the morning peak (7.45am–8.30am).

This was slightly slower than the stretch of South Rd between Tonsley Blvd and Ayliffes Rd. Here motorists heading south travelled at an average of 7.9km/h during the afternoon rush (4.45pm–5.30pm).

It’s no surprise that roadworks have contributed to congestion. In particular, the section of Grange Rd between McDonnell Ave and South Rd was slow during both the morning and afternoon peak, which can be attributed to the Torrens-to-Torrens Upgrade.

Congestion also continued to be a problem for motorists along Main North Rd, with an average speed of 25km/h in the morning peak and 31km/hr in the afternoon.

RAA spokesman Charles Mountain said we’ve been highlighting a number of these bottlenecks for many years.

“We’ve consistently reported how congestion affects Main North Rd, particularly around the intersection with Grand Junction Rd and Port Wakefield Rd.

“On the 700m stretch leading up to this five-way intersection, motorists crawled along at just 9km/h.”

“This section needs to be upgraded, but there appears to be little progress in implementing a solution,” said Mr Mountain.