Saturday, December 02, 2006

Tunnel under Melbourne

A tunnel is again being discussed linking CityLink with Melbourne’s Eastern Freeway. The project estimated to cost $10 billion would link the Eastern Freeway in the east of the city to the Tullamarine Freeway, CityLink and Melbourne’s west. An inquiry will be headed by Sir Rod Eddington who runs Victoria’s Major Events Association. The inquiry starts next year.

I’ll wait and see but I’ll be surprised if this project will ever proceed. The tunnel would have to be tolled and would also need a hefty input from taxpayers. As The Age article points out, the 2003 inquiry into the same project found that 90% of the traffic exiting the Eastern Freeway was bound for the city so the volume of cross town traffic is not currently large. Moreover, some of this traffic will be handled by current proposals such as improving the West Gate/CityLink/Monash corridor. Finally, the geology facing the tunnel is difficult because drilling must proceed through hard basalt.

But mostly I think Steve Bracks is the sort of conservative politician who might not like the risks of this sort of enterprise. Blasting at basalt under the ‘ornate terraces’ of Carlton is unlikely to be popular (Carlton's last liberal might go on the attack) and the Green-leaning strong Labor Seats of Melbourne, Richmond and Brunswick might not be happy with the plan.

My response is predictably to suggest road pricing as a means of cutting into congestion with an accompanying boost to public transport. Interestingly Sir Rod apparently agrees. But supply measures should not be ruled out without thinking carefully about future demand levels even with appropriate charges. I’ll watch this one for a while and follow the Eddington inquiry with interest.


P.A. Coplay said...

I have to wonder how priorities are assigned to different potential transport infrastructure projects. If much of the traffic off the eastern is bound for the city, a better (if it is not as costly which seems quite possible (though am not an expert by any means on this)) infrastructure project to reduce congestion would be the Doncaster railway. The tunnel seems to be join the lines on the map policy.

Maybe even less costly would be subsidizing cheaper and more frequent bus services (am glad to see The Age mentions something like this).

Demand side measures, of course, seem, a less costly measure at any rate.

conrad said...

It would be nice that when they propose these sorts of things, they also list other possibilities for the type of money being suggested. It seems to me you would have 101 different options with $10 billion that might better solve the traffic problems -- and for that matter, if you just use road pricing (like you suggest) and don't spend the money, it could either be given back to the people who generated it (perhaps not a good idea right now), saved for the next recession, or spent on something of potential long-term benefit, like, say, a biotech industry (which, unfortunately, we'd have to trust the government to do).

hc said...

P.a.c., my guess is that congestion pricing access to the city would free up enough road space to make the tunnel redundant.

I agree with your point on priorities. There do seem to be overlaps with preeexisting policies.

I think Labor transport policy rejects new train lines and concentrates on buses.

rabee said...


With differential congestion pricing (different roads have are priced differently) how do we then determine which new roads to construct?

Based on efficient prices? Sounds complicated to me.

hc said...

Rabee, There is some work on this. If one road is unpriced and you are building a substitute for it you might want to know the capacity of the substitute and how to price it. I wrote a paper with Chongwoo Cho on this.

Generally with unpriced other roads you price the other roads less and install less capacity.

If there are many roads unpriced then network effects can make it non-optimal to introduce new links - its a type of Braess Paradox that arises also in computer science.

There are several issues that might interest a theorist such as yourself. For example - proving that Braess type paradoxses don't occur if all roads are efficiently priced.

Network problems in road planning are very complicated since they involve discrete mathematics such as mixed integer-linear programming. Should a link be interested and if so how wide.

But simplier stylised problems could be solved analytically and given interesting interpretations.

Myrtone said...

Some are against it on the basis that we should be encouraging more cars on the road. But if traffic is continuous, it uses less fuel and causses less "pollution" than stop start traffic, there are also fewer accidents. The tunnel woul mean one less lane per direction on Alexander Parade, and maybe room for parking on Princess street. It would also improve traffic flow along Lygon street.

"Maybe even less costly would be subsidizing cheaper and more frequent bus services (am glad to see The Age mentions something like this)."

Busses are boring, no doubt about that.