Rethinking congestion

What could you do with 150 free hours — take up a hobby, learn an instrument, get in a few rounds of golf? Maybe you could add them together for a week away?

It’s a safe bet that you wouldn’t punt for spending them sitting in traffic, but that’s the current reality of congestion in Perth.

Last year anyone taking the average 27km one-way commute across the city centre spent an additional 150 hours — more than six days — sitting in traffic, according to GPS data company TomTom, up more than seven hours from 2023. With a population that grew by about 73,000 in 2023-24, it’s likely the figures in coming years could be higher.

The growing cost of congestion

Car ownership remains high, use of alternative transport remains low, and together with a strong economy, this all combines to keep our roads busy. And while significant infrastructure projects are underway around the city with the goal of making it easier to move between locations, these works also create congestion thanks to road closures and delays.

Each year, Main Roads WA calculates the cost of congestion in the Perth metropolitan area, considering the cost of delay, cost of travel time variability, the impact on vehicle operating costs, and the cost of emissions.

For 2024-25, the annual cost of congestion for Perth metro was a remarkable $2.9 billion, says Mehdi Langroudi, executive director of Network Operations at Main Roads WA.

“Congestion has been increasing year by year, and over the past three years we've seen about a 30 per cent increase in the dollar figure of congestion on our road network on state roads and major local roads,” Langroudi says.

“We've had a significant population increase over the past three to four years in greater Perth, our economy has grown… and that all puts pressure on the road network.

“The government has been spending a lot of money on infrastructure projects as well, and while these are great investments for our state and for our city, roadworks create congestion for the duration that they're happening.”

Where the big bottlenecks are

The top three routes for total congestion are the Mitchell Freeway (which has experienced delays during construction activities), Kwinana Freeway, and parts of Albany Highway.

But other areas are also congestion hot spots. The inner section of Great Eastern Highway and the connection between Graham Farmer Freeway and Orrong Road represent the two locations with the highest congestion cost per kilometre.

Looking at intersections, the worst are Reid Highway and Erindale Road, Tonkin Highway and Welshpool Road East, and the intersection where Leach Highway meets Manning Road.

Bottlenecks, where a road narrows, lanes merge or two roads join, also represent a key contributor — responsible for as much as 68 per cent of congestion, according to Main Roads.

Research looking at a known bottleneck near Whitfords Avenue, for example, shows that while that stretch of Mitchell Freeway should sustain 1880 vehicles per hour in each lane, this falls to 1400 in peak morning periods. In other words, the capacity of each lane falls by almost a quarter, simply because there are so many cars trying to get through.

The impact of congestion on our wellbeing

RAC senior manager Public Policy, Anita McCracken, says members report congestion pressures and less satisfaction with their daily commute.

A few years ago, three-quarters of members said they were ‘satisfied’ or ‘very satisfied’ with their daily commute; that is now the case for only about four in 10. And for those who drive in peak hour five days a week, only one in three is satisfied.

“When asked what modes of transport they use for commuting to work or study, over 90 per cent of our members use a car. So when we're talking about the peak times of the day, that’s going to make a significant impact on congestion,” McCracken says.

“Last year 65 per cent of members said sitting in traffic congestion causes stress and negatively impacts wellbeing, which was up from 56 per cent in 2023. Three-quarters also say they often see drivers frustrated by sitting in traffic or engaging in road rage. In the worst case, this frustration can lead to people getting hurt on our roads.”

Managing congestion with innovation and investment

Congestion is a signal, telling us where people want to go, such as jobs, schools, shops, services, and social connections.

As Main Road’s Mehdi Langroudi points out, “You can't eradicate congestion, because a healthy city does have a certain level of congestion, but you can manage it. We have been widening the freeways and upgrading arterial roads and intersections, and we have been investing in our network, in user technology, and smart freeways.”

One of the clearest signs of that investment is in Intelligent Travel Systems, or ITS, where technology is used to smooth traffic flows and keep roads moving.

Freeway ramp signals have now been added in several locations, along with variable speed limit and messaging signs so Main Roads can slow traffic, divert vehicles around crashes, and reduce the impact of congestion caused by stop-start braking.

Over the next year, the timing of lights at some 150 intersections will be reviewed to improve efficiency and safety. Main Roads says a recent review of one hotspot — the intersection of Canning Highway and Riseley Street to Sleat Road — had already led to a five-minute reduction in travel times for vehicles on the highway.

The State Government has also earmarked more than $485 million to upgrade four key roads in Perth's southern suburbs, including widening Kwinana Freeway between Roe Highway and Mortimer Road.

Infrastructure measures are only a partial fix

It’s well established that new road capacity can also incentivise demand, particularly if it becomes more attractive to jump in the car than on a bus or train. And with each bus capable of replacing up to 50 cars while using just 6 per cent of the road space, buses play a critical role in easing congestion and reducing car dependency, particularly during peak periods.

Last financial year was the busiest on record for WA buses, with more than 85 million passenger movements, nearly two million up on the previous year. Trains had 62 million passenger movements, and even ferries had a record year. New options, such as the Ellenbrook train line, now attract 250,000-odd passengers a month.

Still, the share of public transport compared to private vehicles remains low, and as many as 2.8 million trips a day in Perth are for distances less than 5km by car - journeys that could possibly be switched for other transport modes, including walking and cycling.

“Behaviour change doesn't happen overnight,” Mehdi Langroudi says. “When a train station pops up, people don't just say, ‘As of tomorrow, I'm going to change my behaviour,’ but over time, they notice that there’s a bit of congestion and consider using the train.

“Once they get used to it, they can see it’s a more attractive mode to go to work or go shopping. We're hoping to see a lot more of that over the next few years.”

Without behavioural change, the options for the city become more complex. In other countries, efforts to curb persistent and troublesome congestion include the imposition of charges in inner-city areas in places like London and New York or the introduction of high taxes and barriers to car ownership in places like Singapore.

Paris has introduced a Limited Traffic Zone across four arrondissements with the goal of reducing the 500,000 cars that pass through central Paris daily — half, reportedly, without stopping. It has also restricted car parking for SUVs, banned vans at different times and turned lanes over to bikes and pedestrians.

Integrating land use with transport planning

Main Roads’ Mehdi Langroudi says that for an elongated city such as Perth, the best transport plan is a good land-use plan.

“The focus of employment cannot be just the CBD because our transport infrastructure can’t support everyone coming into the city and going away,” he says.

“If we build employment further away from a central point and build communities around those centres, people don't have to go that far (to work), and their actual commute times are shorter because distances are shorter.”

Anita McCracken agrees and says strong local areas also allow people to make other choices about how they commute.

“Perth is ‘growing up’ and congestion is not just going to magically disappear,” she says.

“We need a range of options, with more done to address the barriers for active travel and public transport in local areas.

“There also has to be careful planning, because there are of course times you may need to be in a car. The goal is to be more efficient with the road infrastructure we have so people can travel more comfortably around by all transport modes.”

While it can be frustrating, congestion is a natural feature of a growing, vibrant city. Choosing to view congestion differently and responding with patience, safer driving, or alternative travel choices can help create a calmer, safer road environment for everyone.