Traffic volumes

We are responsible for managing and operating state government roads effectively and efficiently.

To plan improvements to the road system, we first need to understand how people currently use the existing road network. Traffic volume is a key way we measure this use.

View the interactive traffic map

To see traffic volume estimate information for arterial roads in South Australia, visit the Location SA Map Viewer.

Volumes are shown by different colour bands. Use the 'Legend' button to see what the colours mean.

When you select a coloured road section, you can see:

  • Tesecn Volume: the estimated average number of vehicles using that road section each day in both directions
  • Tesecn Base Year: the year of the oldest survey used to create the estimate
  • Cv Percent: the percentage of commercial vehicles
  • Number Cvs: the number of commercial vehicles.

How we calculate traffic estimates

The Average Annual Daily Traffic (AADT) estimate is the total volume of traffic that pass a roadside observation point over a full year, divided by the number of days in the year. This includes traffic moving in both directions.

Heavy vehicle traffic estimates show the average daily two-way volume of these vehicles. The maps show these as both an absolute number and a percentage of the total traffic flow. We define heavy vehicles as those in Classes 3 to 12 of the Austroads vehicle classification system (PDF, 186.7 KB).

Accuracy and road coverage

This map mainly shows traffic estimates only sealed roads that we maintain. However, we are also adding data for certain outback unsealed roads that we are responsible for.

To balance accuracy with practical data, the road network has been broken down into a series of traffic estimate sections. These are discrete sections of road where the actual values of traffic volumes anywhere along a section are unlikely to vary by more than 10% to 15% from the value shown on the map.

The data shown on this map is derived from a comprehensive database that combines various data sources.

Older maps

We also have older static maps that were last updated in 2015 and are no longer maintained. They display estimated traffic volumes on arterial roads. They cover both rural and metropolitan areas of the state.