A city-wide trial in Melbourne shows how road use charges can reduce traffic jams

Traffic in Melbourne. Image: Getty.

Road congestion in large Australian cities is estimated to cost more than A$16bn a year. Economists have long argued the best way to improve traffic flow is to charge drivers for their contribution to road congestion. We have now analysed data collected from 1,400 drivers across Melbourne to see whether road user charging can change their behaviour in ways that ease congestion.

And the answer is yes.

Because the obstacle to adopting this approach has been concern about its fairness, we also looked at driver incomes. Would congestion-based charges price the poor off the road for the benefit of those who can pay? We calculated how different systems of road use charges affected households on different incomes, and how driving patterns changed under different prices.

The evidence does not support other common policy responses to traffic congestion. Building new roads does little to relieve congestion. Placing tolls on roads can push traffic onto others.

However, even small reductions in congestion can produce large benefits. On congested roads, reducing traffic by 5 per cent can increase traffic speeds by up to 50 per cent.

The question is: what would the optimal charges be? Drivers often plan their travel ahead of time, so Uber-like surge pricing is not necessarily the best way to go. Could simpler fixed charges, based perhaps on time of day or location, be effective?

In 2015-16, Transurban Group implemented the Melbourne Road Usage Study (MRUS) to answer these questions. More than 1,400 drivers across greater Melbourne installed GPS devices in their vehicles for eight to ten months. After a period to establish baseline use, a randomly selected subset faced a series of road use charges via a system of virtual accounts. Every month participants accumulated real money from reduced charges as a result of their decisions about driving.

Well-targeted charges ease congestion

The Melbourne Road Usage Study tested three simple charges:

  • a flat distance-based charge of 10 cents per kilometre
  • a time-of-day charge of 15 cents per kilometre at peak times and 8 cents at other times
  • a distance-plus-cordon charge where drivers were charged 8 cents per kilometre at all times plus A$8 if they entered the inner city.

Our working paper, Can Road Charges Alleviate Congestion?, evaluates the raw data.

Charges that vary by time of day were most effective at reducing driving at congested times. Drivers subjected to a higher cost of driving in the weekday peak hours of 7am to 9am and 3pm to 6pm reduced travel by 10 per cent during these periods.

While a simple 10 cent charge on distance travelled did reduce driving, this was mainly outside the congested inner city and at off-peak times – mostly in the middle of the day and on weekday evenings. Most freeway congestion occurs around morning and late afternoon commutes.

London and Singapore have charges to enter the congested city centre. Further research is needed to assess the effects on inner-city traffic in Australian cities.

The evidence points towards most drivers who enter the central business district (CBD) being willing to pay higher weekday charges. But few drivers entered the cordon zone during the study. Less than 5 per cent of the drivers made over half of the trips into the area.

Access to reliable public transport matters

Public transit has a key role in getting cars off the road. Our data showed households located far from the CBD and from public transport drive more. Living 500m closer to a tram or train station has the same effect on kilometres driven each day as living 5km closer to the CBD.

Households within a 10-minute walk from public transport drive least. The largest reductions in driving from time-of-day and cordon charges come from households living 10 to 20 minutes’ walk away.

Road use charges could be fairer

Congestion-based charges can be a more progressive way to fund roads than the existing system of registration fees and fuel taxes.

The fuel excise makes up almost half of the average annual road bill in Australia. It’s essentially a distance-based fee, but more fuel-efficient vehicles pay less per kilometre travelled. Hybrid vehicle drivers, for example, contribute much less to fuel tax revenue.

Yet, although hybrids contribute less to air pollution, they increase congestion just as much as their petrol-guzzling counterparts. And congestion is a much greater shared economic cost than vehicle air pollution.

Annual vehicle registration fees make up most of the remaining road bill. These provide no incentive to reduce congestion.

Fuel taxes and registration fees put a disproportionate burden on low-income households in the outer suburbs. Our research shows these households would be better off if roads were funded more by congestion charges.

Field experiments help get the settings right

So what is the optimal congestion charge? Economic theory (Pigou 1920) tells us to price at the cost that each extra user imposes on the system.

With road use, though, the calculation is difficult. To fix rates in advance, we would need to know exactly how much longer everyone’s trip is when each extra driver joins each system. And we’d need to cost that slowdown for each individual on the road at that time (i.e. value their time and, potentially, the cost to them of being late). New research has been using clever experimental designs to identify these values.

That said, maybe it is not too important to get the price just right. For electricity, we are starting to see that households respond to there being a price, not its specific level.

Before widespread road use charges are implemented, we would like to see more field experiments like the MRUS to find answers to other questions. Would it be better to combine a time-of-day charge with targeted locations? How effective would it be to charge more for using highly congested arterial roads at peak times? Would this simply push congestion onto nearby local roads? How large a gap between peak and off-peak prices is needed to produce a strong response?

Another interesting option is the i10 model outside Los Angeles. Two lanes are for traffic willing to pay more to get to their destination faster.

Dynamic pricing ensures traffic in these lanes flows freely – if too many use these lanes and traffic slows, the price increases. Drivers can decide every few kilometres if they want to pay more to stay in the express lanes. Those who must get somewhere on time are able to, and the fee revenue can be used to reduce road costs for others.

The Melbourne Road Usage Study (MRUS) shows field experiments can help us design better road use charges. By all appearances, households took it seriously and were positive about their involvement.

The ConversationThe MRUS provides evidence that well-designed road use charges could help reduce congestion by encouraging people to drive at different times, take other routes or use other transport. This could lead to better use of existing infrastructure, thereby reducing costs, while generating revenue for infrastructure investments. Under such a system, drivers who contribute little to congestion could see substantial gains.

Leslie A. Martin, Lecturer (Assistant Professor) in economics and Sam Thornton, Master of Economics candidate, University of Melbourne.

This article was originally published on The Conversation. Read the original article.


“Stop worrying about hairdressers”: The UK government has misdiagnosed its productivity problem

We’re going as fast as we can, here. Image: Getty.

Gonna level with you here, I have mixed feelings about this one. On the one hand, I’m a huge fan of schadenfreude, so learning that it the government has messed up in a previously unsuspected way gives me this sort of warm glow inside. On the other hand, the way it’s been screwing up is probably making the country poorer, and exacerbating the north south divide. So, mixed reviews really.

Here’s the story. This week the Centre for Cities (CfC) published a major report on Britain’s productivity problem. For the last 200 years, ever since the industrial revolution, this country has got steadily richer. Since the financial crash, though, that seems to have stopped.

The standard narrative on this has it that the problem lies in the ‘long tail’ of unproductive businesses – that is, those that produce less value per hour. Get those guys humming, the thinking goes, and the productivity problem is sorted.

But the CfC’s new report says that this is exactly wrong. The wrong tail: Why Britain’s ‘long tail’ is not the cause of its productivity problems (excellent pun, there) delves into the data on productivity in different types of businesses and different cities, to demonstrate two big points.

The first is that the long tail is the wrong place to look for productivity gains. Many low productivity businesses are low productivity for a reason:

The ability of manufacturing to automate certain processes, or the development of ever more sophisticated computer software in information and communications have greatly increased the output that a worker produces in these industries. But while a fitness instructor may use a smartphone today in place of a ghetto blaster in 1990, he or she can still only instruct one class at a time. And a waiter or waitress can only serve so many tables. Of course, improvements such as the introduction of handheld electronic devices allow orders to be sent to the kitchen more efficiently, will bring benefits, but this improvements won’t radically increase the output of the waiter.

I’d add to that: there is only so fast that people want to eat. There’s a physical limit on the number of diners any restaurant can actually feed.

At any rate, the result of this is that it’s stupid to expect local service businesses to make step changes in productivity. If we actually want to improve productivity we should focus on those which are exporting services to a bigger market.  There are fewer of these, but the potential gains are much bigger. Here’s a chart:

The y-axis reflects number of businesses at different productivities, shown on the x-axis. So bigger numbers on the left are bad; bigger numbers on the right are good. 

The question of which exporting businesses are struggling to expand productivity is what leads to the report’s second insight:

Specifically it is the underperformance of exporting businesses in cities outside of the Greater South East that causes not only divergences across the country in wages and standards of living, but also hampers national productivity. These cities in particular should be of greatest concern to policy makers attempting to improve UK productivity overall.

In other words, it turned out, again, to the north-south divide that did it. I’m shocked. Are you shocked? This is my shocked face.

The best way to demonstrate this shocking insight is with some more graphs. This first one shows the distribution of productivity in local services business in four different types of place: cities in the south east (GSE) in light green, cities in the rest of the country (RoGB) in dark green, non-urban areas in the south east in purple, non-urban areas everywhere else in turquoise.

The four lines are fairly consistent. The light green, representing south eastern cities has a lower peak on the left, meaning slightly fewer low productivity businesses, but is slightly higher on the right, meaning slightly more high productivity businesses. In other words, local services businesses in the south eastern cities are more productive than those elsewhere – but the gap is pretty narrow. 

Now check out the same graph for exporting businesses:

The differences are much more pronounced. Areas outside those south eastern cities have many more lower productivity businesses (the peaks on the left) and significantly fewer high productivity ones (the lower numbers on the right).

In fact, outside the south east, cities are actually less productive than non-urban areas. This is really not what you’d expect to see, and no a good sign for the health of the economy:

The report also uses a few specific examples to illustrate this point. Compare Reading, one of Britain’s richest medium sized cities, with Hull, one of its poorest:

Or, looking to bigger cities, here’s Bristol and Sheffield:

In both cases, the poorer northern cities are clearly lacking in high-value exporting businesses. This is a problem because these don’t just provide well-paying jobs now: they’re also the ones that have the potential to make productivity gains that can lead to even better jobs. The report concludes:

This is a major cause for concern for the national economy – the underperformance of these cities goes a long way to explain both why the rest of Britain lags behind the Greater South East and why it performs poorly on a

European level. To illustrate the impact, if all cities were as productive as those in the Greater South East, the British economy would be 15 per cent more productive and £225bn larger. This is equivalent to Britain being home to four extra city economies the size of Birmingham.

In other words, the lesson here is: stop worrying about the productivity of hairdressers. Start worrying about the productivity of Hull.

You can read the Centre for Cities’ full report here.

Jonn Elledge is the editor of CityMetric. He is on Twitter as @jonnelledge and on Facebook as JonnElledgeWrites

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