Peak hour travel speeds on key Adelaide roads have slowed by up to 11km/h in the past decade, an RAA survey shows.
The state’s largest motoring body said its latest travel survey highlights the need for greater investment in the Adelaide road network, including the completion of the North-South Corridor.
Of the seven routes studied over the past decade, traffic moved slower on Brighton, Marion, Main North and North East roads, during both morning and afternoon peak periods, while only Goodwood Road improved in both peaks.
RAA’s Senior Manager Road Safety, Charles Mountain said the 2018 survey demonstrated that many key Adelaide thoroughfares were still not coping with increases in traffic volumes.
“Traffic congestion is not just a problem for motorists and bus services – it’s also bad for the environment and the economy,’’ he said.
“In particular, large sections of the inner-city ring route and main roads are struggling during peak periods, and more needs to be done to improve capacity.
“For a city the size of Adelaide, it’s unacceptable that motorists should have to deal with such high congestion levels.”
This was highlighted in a national report on traffic congestion by Australian Automotive Association (AAA) last year, which named Adelaide as Australia’s third most congested capital city, behind Melbourne and Sydney.
However, Mr Mountain said North-South Corridor infrastructure projects – which included the recently opened Torrens-to-Torrens motorway and Darlington Interchange to be completed by the end of 2019 – would help improve traffic flow.
“We also need to look at extending clearway restrictions, which has worked on Greenhill Road, and reducing congestion at key intersections such as Grand Junction and Main North Road,’’ he said.
RAA’s comparison of the key routes surveyed at 8am and 5pm on weekdays in 2008 and 2018 showed.
Marion Road’s average speed slowed from 27km/h to 23km/h in the morning peak and from 27km/h to 19km/h in the afternoon peak.
Main North Road’s average speed slowed from 34km/h to 27km/h in the morning peak and from 36km/h to 35km/h in the afternoon peak.
Brighton Road’s average speed slowed from 32km/h to 27km/h in the morning peak and from 35km/h to 24km/h in the afternoon peak.
North East Road’s average speed slowed from 35km/h to 31km/h in both the morning and afternoon peaks.
Fullarton Road’s average speed increased from 23km/h to 27km/h in the morning peak but fell from 25km/h to 23km/h in the afternoon peak.
Unley Road’s average speed increased from 15km/h to 25km/h in the morning peak and recorded 24km/h in the afternoon peak for both years.
Goodwood Road’s average speed increased from 18km/h to 32km/h in the morning peak and from 23km/h to 27km/h in the afternoon.
(South Rd was not included in the 2008 survey as travel speeds were compromised by the Gallipoli Underpass roadwork restrictions).
Mr Mountain said Marion Road travel speeds had deteriorated as some traffic had transferred to it from South Road to avoid the Darlington Interchange roadworks, which began in 2016.
“The 2008 and 2018 figures show traffic travelling both ways along Goodwood Road between Greenhill and Cross roads has fallen by 5,000 vehicles a day,” he said.
“This has improved travel speeds along Goodwood Road as some traffic has moved to South Road to take advantage of the Gallipoli Underpass and Glenelg tram overpass at Glandore which have been completed during this ten year period,’’ he said.
Tags: RAA travel survey
