Why do the worst infrastructure projects get built?

Inaccuracy of transportation project cost and benefit estimates by type of project, in constant prices (Flyvbjerg)

Under-estimating the cost of major infrastructure projects and over-estimating the demand is so chronic that forecasters deserve some harsh medicine, according to Professor Bent Flyvbjerg from Oxford University’s Said Business School. He says “some forecasts are so grossly misrepresented that we need to consider not only firing the forecasters but suing them too – perhaps even having a few serve time”.

Australians have plenty of experience with underperforming infrastructure projects. For starters, just in transport alone, there’s Brisbane’s Clem 7 road tunnel, Sydney’s Lane Cove and Cross City tunnels, the Brisbane and Sydney airport trains, Melbourne’s Myki ticketing fiasco, and the 2,250 km Freightlink rail line connecting Adelaide and Darwin. And they’re just the ones we know about!

Professor Flyvbjerg says cost overruns in the order of 50% in real terms are common for major infrastructure projects and overruns above 100% are not uncommon. Writing in the Oxford Review of Economic Policy, he argues that demand and benefit forecasts that are wrong by 20–70% compared with the actual outcome are also common.

Transport projects are among the worst performers (see exhibit). Professor Flyvbjerg examined 258 transport projects in 20 nations over a 70 year time frame. He found the average cost overrun for rail projects is 44.7% measured in constant prices from the build decision. For bridges and tunnels, the equivalent figure is 33.8%, and for roads 20.4%. The difference in cost overrun between the three project types is statistically significant and the size of the standard deviations shown in the first exhibit demonstrate the high degree of uncertainty and risk associated with these sorts of projects.

He also found that nine out of 10 projects have cost overruns; they happen in all nations; they’ve been a constant over the last 70 years; and cost estimates have not improved over time.

And it’s not just under-estimation of costs. Errors in forecasts of travel demand for rail and road infrastructure are also endemic. He found that actual passenger traffic for rail projects is on average 51.4% lower than forecast traffic. He says:

This is equivalent to an average overestimate in rail passenger forecasts of no less than 105.6 per cent. The result is large benefit shortfalls for rail. For roads, actual vehicle traffic is on average 9.5 per cent higher than forecasted traffic. We see that rail passenger forecasts are biased, whereas this is less the case for road traffic forecasts.

He also found that nine out of ten rail projects over-estimate traffic; 84% are wrong by over ±20%; it occurs in all countries studied; and has not improved over time.

Thus the risk associated with rail projects in particular is extraordinary. They face both an average cost overrun of 44.7% and an average traffic shortfall of 51.4%. Read the rest of this entry »


Would we build another Opera House?

The other 'Melbourne Opera House' - Powlett St East Melbourne

An argument I see frequently in relation to massive infrastructure projects like High Speed Rail (HSR) is that we should simply get on and build them because they’re ‘visionary’ and ‘nation building’. For example, a commenter recently likened investment in HSR to the decision to build the Sydney Opera House. If cost-benefit analysis had been done on the Opera House, he argued, it would’ve been still-born. Thus we would’ve been denied the enormous tourism revenue and the boost to national pride provided by this magnificent building.

I expect he’s right. Formal cost-benefit analysis would probably be hard-pressed finding that the benefits of any opera house exceed the costs, either then or now. There’s therefore always a chance if you look too hard at the costs and the risks you could end up missing out on some whopping future benefits. However the problem with this sort of argument is that it’s based on hindsight. We know for a fact from the perspective of 2011 that the Opera House is a grand success. But cost-benefit analysis isn’t retrospective, it’s prospective – it helps us to evaluate projects before we commit to building them.

Here’s a “thought experiment”. Consider a contemporary proposal to spend a fantastic sum of money on (say) The Melbourne Opera House (insert your city of choice). Imagine an architect of Frank Gehry’s stature (but please not Frank himself!) was asked to ignore the cost and come up with a design that would create an “international icon”. The promise is the building would “put Melbourne on the map” and more than repay the preposterous cost over the years in tourism revenue and civic pride. Of course while it would nominally function as an opera house, what we’d really be building is a piece of architecture so powerful, distinctive and attractive, that it would be as iconic as……well, the Sydney Opera House.

The trouble is the probability of achieving this vision is close to zero. No one knows what the recipe for international icons is. We can look back and more or less pick out the vital decisions and factors that made the Sydney Opera House the symbol it is today, but doing it prospectively is close to impossible. We’d almost certainly end up with a Melbourne Opera House that was functionally compromised and cost billions more than it needed to, but which nobody outside Victoria gave a second glance.

Actually even if the Sydney Opera House planners knew with certainty in the late 1950s what we know now, I’m not sure building it would’ve been the “right” decision to take at the time. The Sydney Opera House didn’t instantly become an international symbol so most of the tourism and “icon” benefits, which probably didn’t kick in seriously until at least the 1980s, would’ve been heavily discounted back to the time the decision was taken to proceed. The net present value of the benefits might not have exceeded the cost of construction which, let’s not forget, was very high. Read the rest of this entry »