Telematics first measures major city performance; heavy-rigid figures trend down
The Bureau of Infrastructure and Transport Research Economics (BITRE) has released significant industry-related information on congestion and heavy-vehicle fatalities.
The more recent report, Freight vehicle congestion in Australia’s five major cities – 2019, sees telematics data brought to bear on the issue in the first of a planned annual series focused on 53 selected routes across mainland state capital cities, barring Darwin.
“The selected routes comprise the major motorways, highways and arterial roads within each city that service both passenger and freight vehicles,” the report stated.
It tracks congestion of selected routes from across Australia’s major cities by estimating travel times based on observed speeds of freight vehicles.
The paper presents two ‘congestion’ measures for each route, BITRE noted.
The first is the Mean Excess Time Ratio (METR) which reflects the how much the average expected travel time across the day exceeds the best, or lowest, expected travel time. Theseare usually in the early hours and are assumed to be close to free running conditions.
The second is the Mean Excess Uncertainty Ratio (MEUR) which reflects how much the average uncertainty – measured as the breadth of the interquartile range, or the middle 50 per cent of trips – exceeds the lowest observed uncertainty.
“The lower the uncertainty, and the narrower the interquartile range, the more certainty a firm can have about how long journeys will take and their ability to provide deliveries at agreed times,” the report stated.
“Because firms are bound by speed limits, this uncertainty usually means more ‘downside risk’, with below average travel time more likely to be slower than above average times are swifter.”
It adds that these measures are only indicators of congestion and may be prone to ‘noise’ especially for routes or times of day, such as the early morning, with relatively sparse data.
They also do not distinguish between a peak that lasts one hour and a peak that spreads over several.
This initial report highlights several features of traffic congestion on the selected urban routes, including:
- Motorways exhibit more distinct peak periods than surface routes.
- Surface routes (those not on grade-separated motorways) show more ‘base level’ uncertainty, which is most likely due to intersections and traffic lights.
- Congestion peaks are usually attributable to commuter traffic to or from work and education – for instance motorways tend to show morning peaks moving towards the CBD and afternoon peaks moving away from it. “This is supported by prior BITRE telematics work that found travel peaks effectively disappeared on urban freight routes during Covid-19 lockdowns (BITRE 2020),” the repost said.
- A number of surface routes in all cities also exhibit an unexpected third peak in the early morning, around 4-5am. “The reasons for this third peak are not clear, although freight specific activity or road works are potential reasons.”
- Intersections on surface routes and interchanges on motorways, are prominent locations of delays in peak periods. “To some extent, this captures delays for vehicles entering and exiting the route rather than vehicles travelling the full route.”
BITRE calculated composite measures of congestion for each city, and have indexed them to 1 for 2019. These measures are not comparable between cities, but can be used to track changes in congestion across all selected routes in each city over time.
Read about the federal government’s freight data hub pledge, here
The report paper uses data from the BITRE telematics project.
It “transforms GPS traces from freight vehicles of private road freight operators into data about Australia’s road freight industry and road freight network, to help inform industry, government and other interested parties”, using BITRE’s independently developed Yulo framework, the bureau said.
“This data can help inform planning and investment in the road network and rest areas, inform industry and government on economic activity and assist trip planning among other things.
“By tracking the entirety of vehicles’ journeys, it can generate data on more parts of the road network than is practical using conventional road data collection means such as fixed cameras or pneumatic tubes.”
The report is said to be based on more than 60 million observations from more than 5,000 road segments whilst the database contains billions of observations on more than 700,000 road segments.
The full report can be found here.
Heavy vehicle fatalities
Meanwhile, the bureau’s ‘Fatal heavy vehicle crashes Australia quarterly bulletin’ for April to June this year, shows heavy rigid figures continuing to plunge while those for articulated trucks have has hit a standstill.
The 12 months to the end of June saw articulated truck fatal crashes zigzagging across the 90 mark over the past seven years, with this year, at 91, refusing to take last year’s lead of 80.
Heavy rigids have also shown volatility but in the past four years fell from around 80 to 57.
The 10-year trend remains promising but with a reversal for that of the past three years.
So, whereas articulateds are down 3.2% since June 2012, they are down just 0.4% since June 2019.
For heavy rigids, those figures are down 1.4% and 11.9% respectively.
On a state basis, Queensland crash deaths for articulateds are hurting the downward trend, with the state hitting double figures for the middle two of the previous four quarters – 14 and 13.
The only other state to do so since September 2018 was New South Wales at 11 for June quarter 2020.
On an annual basis, after four years with deaths around the 23 mark, they shot up to 42 in the year to June.
By contrast, heavy rigid crash deaths have been in single figures in all states since June 2020 and, annually, down between 18.9% and 11.9% over the past three years.
In all, for the 12 months to the end of June, 159 people died in crashes involving heavy trucks, with 100 deaths in crashes involving articulated trucks and 61 deaths in crashes involving heavy rigid trucks.