|City:Link from the air|
It seems likely the Gillard government will find itself compelled to come on board before the next federal election. Daniel Andrews, the ALP leader in Victoria, can be expected to follow suit.
So, I ask, what is this road tunnel supposed to do? To relieve traffic congestion, stupid! Well, no actually.
The underlying purpose of the tunnel is to return a positive economic and social benefit to the state of Victoria and, more specifically, to metropolitan Melbourne.
The main economic justification for building the tunnel is that it will reduce time spent travelling and speed up traffic in Melbourne's entire inner and middle suburban road network. But plainly, it is not justified to spend the billions of dollars required to build the road tunnel just to speed up by a few minutes the journeys of drivers travelling all the way across the city. Nor is it justified if building the tunnel merely attracts more people to use their cars and shifts the congestion to local roads and the exit ramps.
Eddington's own consultants could only come up with a return of 46¢ in economic value over its 30-year life for every dollar spent on it. In other words, it's a loss-making project for Victoria.
A recent study of the promises made for CityLink and the subsequent outcome shows what is likely to happen with the road tunnel. Before CityLink was built it was calculated that motorists would save between 31,800 and 37,900 vehicle hours a year by 2001. Average travel speed over the whole day would increase by about 1km/h.
In fact by 2001 - after CityLink was completed - traffic across the urban network was moving slower than had been predicted for the road network without CityLink (42km/h compared with 43.3km/h on average). Further, motorists were spending more, not less, time on the road per day.
The problem is that motorways, just because they are magnificent roads, attract traffic to them. Moreover, motorists must use local roads to reach the motorway, and then to leave it again to reach their many, widely dispersed destinations.
Time that may be gained on the motorway is lost again on the local road system and the exit ramps. And the extra congestion created becomes a justification for the next round of motorway building - as in fact happened with CityLink.
However, the projected economic cost of congestion, which is always used in justifying motorway construction, is vastly inflated. About 60 per cent or more of the ''cost'' used in benefit-cost calculations comes from putting a money value on each motorist's allegedly ''saved'' travel time. Mostly, the saved time per journey per motorist per day is only a few minutes, but when expressed in terms of money over the life of the motorway, all these little amounts of time ''saved'' add up to a very large sum for the billions of journeys made every year.
There is no evidence that, even if these few minutes per journey were saved, the time would be spent productively - for instance, buckling down to a few minutes' extra work every day. It is just as logical for a motorist to sleep in for a few more minutes, which may or may not be economically productive. However, there is evidence that what motorists actually do if the speed of travel increases is not spend less time travelling every day, but instead travel more and further.
So what can we expect the outcome to be if the road tunnel is built? At first the tunnel will attract people to use their cars, thus congesting local roads and impeding essential freight traffic flows. As a consequence, the speed of traffic in inner and middle Melbourne will slow further. Second, if journey speeds do increase, there will be more car travel and carbon emissions, which is not a good result for the changing climate or for Melbourne's urban sprawl.
The long-term answer to congestion is to build the public transport system into a highly efficient, fully integrated network.
The money projected to be spent on motorways in the next 50 years should be spent modernising and expanding the rail, tram and bus system and managing it under unified command, like the seamless networks seen in the finest European cities.
This is based on the article ''Rethinking the cost of traffic congestion, lessons from Melbourne's CityLink toll roads'' in Urban Policy and Research by Nicholas Low, professor in urban and environmental planning at Melbourne University, and John Odgers, senior lecturer at the RMIT school of business.