Daily traffic across Punt Rd bridge (click)

In Elliot Perlman’s Melbourne-based novel, Three dollars, Eddie thinks the only advice he could offer his daughter is the solution of differential equations and an insight into which trains go via the city loop and why. He imagines that on his deathbed and with his last breath he would say: “Abby, my darling daughter, remember this: no matter where you are or what time of day it is – avoid Punt Road”.

Eddie’s fatherly advice is borne out by the numbers in VicRoad’s Hoddle Street Study: existing conditions summary report. It shows that 10,000 vehicles per hour travel on Hoddle Street in the middle of the day, only a little more than the 9,700 per hour that use it in the morning peak. And as the accompanying graphic of traffic volumes across the Punt Rd bridge shows, traffic on Saturday and Sunday is higher than on Monday, Tuesday and Thursday.

So if you think the Hoddle St corridor is always busy you’re right. The two-way traffic volume on Hoddle St in the section between the Eastern Freeway and Victoria Pde is 85,000-90,000 vehicles per day. There are also a further 27,000 bus passengers on a weekday, so the number of people travelling along Hoddle St is large. This is a conservative estimate – it doesn’t count passengers in cars.

What to do about Hoddle St is a difficult question and I’d like to hear some suggestions. The Baillieu Government is reported (here and here) to have shelved work on VicRoad’s study of options for the corridor. The remaining money has instead been transferred to the study of the proposed Doncaster rail line. This makes sense politically if the Government feels it is obliged to deliver on the railway line. It could argue that the train will reduce traffic congestion, and thereby make the significant cost of upgrading Hoddle St unnecessary.

While it might fly politically, it’s hard to see that a Doncaster rail line would make much difference to conditions on Hoddle St. The space vacated by any drivers transferring to rail would in due course be filled by others, so it would have no lasting impact on traffic congestion. Not that it’s likely many car commuters would even elect to use the Doncaster train instead of Hoddle St.

As I pointed out here, analysis of journey to work data from the 2006 Census undertaken for the Eddington Report shows the number of workers living in the municipality of Manningham who commuted to the City of Melbourne at the 2006 Census was small – just 8,500 (i.e. 17,000 two-way trips). And the number is declining – this was 700 fewer than in 2001. Nor is this group likely to get much bigger due to growth, as the population of the municipality of Manningham is projected to increase by a paltry 0.7% p.a. out to 2031.

Of these 8,500 commuters, 5,100 drove to work and 3,150 already took public transport. The latter group mostly used buses but a third used the Hurstbridge and Belgrave-Lilydale rail lines in neighbouring municipalities (this was before the new Doncaster Area Rapid Transit services started late last year). If a new Doncaster rail line were to achieve the same mode share as in nearby municipalities like Whitehorse, Banyule and Maroondah that already have rail, around 1,600 Manningham commuters could be expected to stop driving to work and change to public transport. That does not seem a very large number in the context of the likely cost of a Doncaster rail line. Even assuming those 1,600 all currently use Hoddle St to get to the City of Melbourne, that’s only a reduction of 3,200 trips.

Getting city centre workers who currently drive out of their cars and onto public transport won’t be easy. As I pointed out here and here, commuters who work just beyond the Hoddle grid are more likely to drive than take public transport, notwithstanding traffic congestion.  Many workers who drive have high status jobs – it’s likely they enjoy the use of a subsidised car and parking, meaning restrictions on cars would have to be very onerous before they’d shift across to public transport.  Another issue is that many Hoddle St users work on the fringe of the CBD or in the inner city – many would have to change modes if they used public transport, thereby increasing the duration of their journey to work.

Another approach to the Hoddle St problem is to upgrade the road. Since 6,400 vehicles cross the corridor east-west in the morning peak, grade-separating key intersections is probably the most likely upgrading scenario. While this wouldn’t provide anything more than a short-term reduction in congestion, it would nevertheless add to capacity i.e. more traffic could move along the corridor than is currently the case. Upgrading could be a trade-off for providing dedicated 24/7 lanes for buses on both sides of Hoddle St. While increasing capacity should provide economic benefits, that would depend on the cost of upgrading, so detailed analysis would be required. I expect the cost of construction and disruption to existing traffic would be enormous – perhaps not as much as a Doncaster rail line, but probably not that much less either.

However putting a price on the use of the Hoddle St corridor when it’s congested – necessarily as part of a wider scheme – would be the “first-best” option. A congestion price would discourage low value trips and could keep traffic moving (although still well below maximum posted speeds) without upgrading (although it’s possible grade-separation might still make economic sense). Of course road pricing is a politically difficult strategy and would probably be the last choice of government.

What to do about Hoddle St is a hard one. The only plausible technical solution in my opinion – congestion pricing – is very hard politically. On the other hand, the do-nothing option is attractive to politicians because people who hold government’s accountable for the quality of public transport nevertheless seem to accept politicians can’t do much about congestion. But congestion imposes a large cost, especially in terms of time lost. Anybody got a solution?