THE BUREAU of Infrastructure and Transport Research Economics (BITRE) has released its 2023 report on freight vehicle congestion in Australian capital cities.

The fifth issue in the annual series uses freight vehicle telematics data to analyse traffic congestion across Sydney, Melbourne, Brisbane, Adelaide and Perth, as well as Hobart for the first time, for the calendar year 2023.

BITRE analysed a total of 73 routes comprising major motorways, highways, and arterial roads that service both passenger and freight vehicles.

The data provides estimates of congestion based on the length of journeys when compared to the same route during a baseline of uncongested conditions, as well as measuring uncertainty in travel times.

The 2023 report marks the second year since the first report in 2019 where no capital cities experienced lockdowns due to Covid-19, and the report suggests that in 2023, congestion levels returned even closer towards pre-pandemic levels (2019).

The report identified a number of trends in congestion across the major cities, primarily using two indexes; Mean Excess Time Ratio (METR) and Mean Excess Uncertainty Ratio (MEUR) to present these trends.

These indexes measure by how much travel time along the chosen routes exceeded the best expected time, and the uncertainty in travel time respectively.

Compared to BITRE’s 2022 report, city-wide vehicle congestion as measured by METR increased (or worsened) in Perth, remained unchanged in Brisbane and fell (or improved) in Sydney, Melbourne and Adelaide.

Meanwhile, congestion uncertainty or MEUR again worsened in Perth, remained the same in Melbourne, and improved across Sydney, Brisbane, and Adelaide when compared to 2022.

Whilst there were also two routes analysed for Hobart, the data was insufficient to produce a city-wide measure.

An interesting detail of the report was an unexplained “third peak” observed on many arterial roads between midnight at 0400, also present in each of the four prior BITRE reports, the cause of which remains unclear.

The report noted the estimates for 2023 are derived from a smaller pool of data, and as such must be treated with caution.