Crashes on our roads
are reducing over time
Our road safety approach acknowledges that things can go wrong on any road: people will make mistakes, vehicles will break down, and risks will be taken. Our approach also acknowledges that all people are vulnerable on any road.
To reduce the risk of things going wrong—and to reduce the risk of serious consequences—we implement safety measures such as speed limits, barrier walls, lane markings and signage at key points on our roads.
We also learn from incidents that do happen and act to prevent them happening again. This is why, as our graph here shows, both injury and non-injury crashes on our roads have dropped over time.
We note that, while this graph combines all injury crashes, some of our data refers to serious injury crashes and minor injury crashes. A serious injury crash is a crash resulting in someone being transported by ambulance. A minor injury crash is a crash where someone requires first-aid but does not need ambulance transportation.
More travel, less incidents
Between 2015 and 2021 Transurban acquired more roads and added new lanes to existing roads.
All up, vehicle kilometres travelled on our roads have increased by nearly 40%.
But incidents have continued to decrease, demonstrating our approach is making our roads safer over time.
Types of crashes
Three most common crashes on our roads (2015–21)
While crashes on our roads are rare, when incidents happen, they're usually one of three common crash types.
of crashes are
Crashes in which a vehicle collides with the vehicle in front (crashing into the forward vehicle’s rear-end). Rear-enders often occur when a vehicle brakes suddenly—or when roads are congested and vehicles are queuing ahead—and the driver behind fails to respond/slow in time.
of crashes involve
an out-of-control vehicle
An out-of-control crash is a crash involving loss of control of a vehicle. Distraction and speed both contribute—speeding and distracted drivers have less time to react when road conditions change—and may brake or turn too fast and lose control.
of crashes are side swipes,
including merging crashes
When a vehicle crashes into another vehicle travelling alongside, that’s a side-swipe. Merging crashes are usually side-swipes, including when a driver, attempting to exit the motorway (often too late or from the wrong lane), collides with a neighbouring vehicle.
71% of crashes on our roads
are the three most common types
All crash types are rare on our roads, but they can happen. This chart shows the proportions of the three most-common crash types on our roads, compared to other crash types.
Other incident types (that, when combined, account for just under 30% of incidents) include:
As shown, all these crash types are even rarer than our most common crash types.
While rear-enders are consistently the most common crash type on our roads, numbers vary from year to year, and the frequency of other common crash types (including ‘object hit’) varies over time. Overall crashes are trending downwards, even while the number of roads we operate has increased.
The sharp drop in 2020 and 2021 reflects the reduced number of vehicles on our roads due to the various travel restrictions in place in response to the COVID-19 pandemic.
The roadside and other technology systems we operate to support safe travel are also contributing to reduced incidents on our roads. We've improved the accuracy of our data-capture processes over time, leading to improved incident categorisation. This graph reflects this, with some crash types appearing to increase as they are more accurately categorised.
Crash risk factors
How different driving conditions impact safety
Even if you drive the same road regularly, your driving experience will vary. Some days it’ll be raining or overcast. If you're driving at peak hour, you might encounter congestion. If you're driving late at night, you could be fatigued, or your visibility could be reduced.
You get the idea: driving conditions are always changing. But which driving conditions are associated with higher crash risks? We’ve captured data on different driving conditions that can play a role in safety outcomes.
Serious injury crashes are more likely
to occur on Sunday evenings.
Moderate congestion is also a
factor in crash severity outcomes.
Some incidents increase on our roads in wet weather, but crash severity does not increase.
Time of day
Serious injury crashes are more common during the evening.
A serious-injury crash is a crash where someone needed to be transported in an ambulance.
Evenings are associated with a higher incidence of serious-injury crashes on our roads (20% of all evening crashes involve serious injuries, compared to 15% in other time periods).
The factors that contribute to serious-injury crashes are complex, but driver fatigue combined with higher speeds and more open roads contribute to the increased injury severity associated with evening crashes. Alcohol and drug consumption can also be contributing factors.
Sundays and serious crash injuries
Sundays are also associated with a slightly higher incidence of serious crash injuries on our roads. On Wednesday and Thursday, the proportion of incidents where no one is injured is slightly higher than on other days of the week.
Data deep-dive: day and time crash outcomes
Comparing the proportion of serious-injury crashes in all our markets combined, and across different time periods, serious injury crashes are proportionally highest (36%) on Sunday evenings.
Congestion and overall traffic speeds are a factor in how serious a crash is. Serious-injury crashes occur most frequently when congestion is moderate and vehicles are travelling at around 40kph, comprising 24% of all crashes occurring under these traffic conditions. The proportion of serious injury crashes that occur in stop-start traffic—when vehicles are, in layperson’s terms, ‘crawling along’—is only 2%.
While speed is a factor in the seriousness of crash outcomes, congestion also contributes. As shown, the proportion of serious-injury crashes is lower (12% of crash outcomes) when traffic is free-flowing (above 60km/h).
The peak-hour ‘bump’
On each of our roads, a handful of incidents may occur in a day—they don't happen often. But, during peak travel times, across all our roads, rear-end crashes increase by 51%.
By contrast, out-of-control crashes are proportionally higher outside peak periods (up by 17%) compared to peak periods. During non-peak periods, traffic is lighter and higher speeds are more likely. These factors combine to increase the risk of losing control.
The data also shows side swipe incident numbers are not significantly impacted by congestion levels.
Out-of-control crashes happen twice as often when it’s raining (29% of all incidents) compared to when it’s sunny (14% of all incidents).
Wet roads, especially after a dry period, can affect vehicle braking and steering performance: with water on the road, there’s less grip. Worn tyres and tyres with less-than-optimal tyre pressure can also impact both performance and driver reaction times. Further, the reduced tyre-road traction means vehicles are more likely to skid—causing loss of vehicle control.
Driving in heavy rain also reduces visibility—making it hard to see other vehicles and the road ahead and reducing drivers’ ability to identify and respond to changes. Late reactions often involve swerving, hard braking or both, leading to skidding and loss of control on a wet road.
Crash severity in wet road conditions
Even when it’s raining—and crash risk is higher—the proportion of serious injury crashes on our roads remains relatively static. This is because our roads include design features that minimise crash impacts. If a motorist loses control on one of our roads, the risk of serious injury is reduced when compared to other roads. This is part of why our roads have been found to be twice as safe as like roads.
Further, we constantly assess all our roads and tunnels to identify hazards and driver behaviour patterns that could lead to increased crash frequencies or more severe crash types. Our new road design solutions are thoroughly assessed to identify and remove potential serious crash risks. For example, where a risk of serious injury is identified, we may change the design or we may implement additional safety measures such as reduced speed limits, barrier walls, guard rails and signage.
Our roads and tunnels are built to function in all kinds of weather. During the March 2022 flooding events in Queensland and New South Wales, our roads and tunnels remained operational throughout, providing accessible travel routes for those affected by the floods.
High-quality roads enhance safety outcomes
The high functionality of our roads, and the various safety features embedded into them are helping keep our customers safe, as our data shows.
Transurban roads are maintained to high standards and road surfaces are regularly checked and refreshed. This reduces the risk of crashes in the wet.
Using data to reduce crashes
Targeting key incident types
All data we collect on our roads is put to good use—helping ease congestion, reduce customer travel times and improve safety.
Here's how we use data to improve safety in three key areas.
Targeting common crash-types
Our road safety approach acknowledges that even on the safest roads, people will make mistakes and crashes will happen. Here are some of the ways we use data to reduce both the risk and severity of the three most common crashes on our roads: rear ender, out-of-control and side-swipe.
Our roadside technologies—such as sensors, CCTV cameras and (non-identifiable) vehicle GPS data capture—give us insights into traffic behaviour at specific on- and off-ramps. We use this data to identify safety enhancement opportunities.
Data captured via roadside technology also informs our incident response planning. We use data to identify when and where our incident response teams and vehicles should be located. This helps teams mobilise to incidents faster.
Variable signage lets our control centre operators make rapid traffic management changes when needed. For example, when an incident is in progress, our operators can automatically close the affected lane, reduce road speeds and even send targeted messages to motorists.
These measures help us clear incidents faster, maintain traffic flow and keep everyone safe while navigating the changed conditions.
Signal phasing adjustments
Traffic patterns change over time, and this can often change the number of vehicles using intersections and ramps connecting with our motorways. On Sydney’s Eastern Distributor, traffic data showed an emerging pattern of crash incidents at the William Street on- and off-ramps.
We collaborated with our NSW Government partners to adjust the traffic signal phasing at this intersection and ensure drivers had adequate time to move safely on and off our road, reducing the risk of side-swipe crashes.
Smoothing out merging lane access and improving lane legibility reduces the risk and severity of side swipes incidents. We improved signage and lane markings along CityLink before the Batman Avenue exit to make it easier for customers to navigate when and where to exit. These improvements are helping prevent last-minute lane changes as vehicles exit the road.
We also install advance warning signs on our roads to help drivers select the correct lane when approaching off ramps.
Reducing congestion is critical to further improving safety on our roads. We focus a lot of our attention—our technical expertise, operational know-how, road infrastructure and educational campaigns—on easing congestion on our roads.
We also use data to manage congestion both in real-time and via long-term enhancement projects.
We use radar detectors to track traffic speeds and congestion and can also spot crashes and lost loads. When an issue is detected, our 24-hour traffic control room operators receive an instant alert.
Based on this data, operators can then increase or decrease speeds, open or close lanes and make other adjustments to optimise traffic flow and ease congestion, and deploy incident response teams to clear the road, also easing congestion.
We use artificial intelligence (AI) technology to better manage peak traffic flows.
This smart system technology learns on the job, analysing data captured through its operations to improve motorways operations, including prioritising critical events.
Some of our roads use ramp metering technology to manage traffic flow during peak periods. If you’ve ever approached a toll road and encountered signage directing when to enter the motorway (often a red light for wait, and a green light for go)—you’ve encountered ramp metering.
Spacing vehicles out as they enter increases average speeds and trip durations, making trips faster for you and safer for everyone on the road.
In CityLink's Burnley Tunnel a common optical illusion in sloping tunnels means drivers may not realise they are climbing as they exit. When they don't accelerate enough, they slow down, leading to congestion.
Following a VR lighting trial we are preparing to install pacemaker lights, designed to provide visual speed cues. These will help drivers maintain appropriate speeds, reducing both congestion and incident risk.
Targeting wet weather events
Before, during and after heavy rain events, we conduct multiple activities to ensure safe travel for our customers.
When heavy rain is forecast, depending on the severity of the event, we conduct systematic checks to ensure our road and tunnel equipment (including drainage) is fully operational and ready to deal with the deluge.
Road operation measures
During weather events, depending on the conditions, we will introduce safety measures such as reduced speed limits, lane closures and updated travel advice messaging along our roads to provide additional guidance to motorists as needed.
Extreme rain, wind and other weather events can also lead to increased incidents on our roads. So we ensure our incident response teams are fully resourced and located at points where we can rapidly deploy as needed.
During and after extreme weather events such as major flooding events, we collaborate with emergency services, providing information on routes and road access to ensure help is getting where it needs to be as quickly as possible.