An excellent road network does not come about by accident. It requires careful, well-integrated planning over the entire metropolitan area, over many decades, as well as a will to implement these plans, and a commitment to see them through to completion. Unfortunately, Adelaide has a sad history of great plans that were never implemented, and successive governments (of both major parties) have made disastrous short-term decisions such as selling off land that was purchased for the construction of freeways. If not for these epic stuff-ups by past governments, Adelaide could have had a complete north-south motorway from Gawler to Old Noarlunga for a fraction of the $4.67 billion that has been spent on the north-south corridor so far, not even including the $15.4 billion that the Torrens to Darlington project is expected to cost if built with tunnels.

Now, the government and transport department are promoting their tunnels plan as if it will be such a great thing, something to be proud of. I’ve heard people say “Adelaide is finally getting tunnels”, as if that’s something to be proud of, like it means we’ve finally made it into the ranks of great cities that have freeway tunnels. I groan inside when I hear this, not only because of the exorbitant cost and bad planning outcomes that this particular tunnels plan would involve, but because tunnels are usually not something a city should be proud of. On the contrary – tunnels are a sign of shame. Not in every case, but in many cases around Australia, tunnels are actually a sign of poor planning. Their presence means that someone, at some time in the past, stuffed up. If they had planned well, they should have been able to foresee the need for such a road, and acquire the land necessary for its construction, decades in advance.

For an example of this, look no further than Adelaide’s north-south corridor (but it’s by no means the only example). We actually had the land for construction of such a motorway more than 40 years ago, as it was purchased as part of the MATS plan, shown in the image above (though the freeway alignment would have been slightly different, it would have served much the same purpose). If governments had not sold this land for some quick cash, we wouldn’t even be thinking about building tunnels now.

But even now, tunnels are not the cheapest option, and certainly not the best option when other factors (such as provision of entries and exits, or connection to future motorways) are considered. But we have a government that has so far lacked the courage to make the right decision about this, and a transport department that seems to take pride in delivering large, complex projects rather than low-cost, simple ones. So they proudly display images of tunnels to the very people who have to pay for those tunnels, all because they didn’t do their planning job properly years ago.

And this isn’t the only shameful thing we see governments taking pride in.

All too frequently, we see governments boast of the cost of a project as if spending more money is a good thing, when instead we should be asking what value we’re getting for that money. Similarly, governments will often boast about the number of jobs created during a project’s construction, as if creating jobs is the objective. We see this with the Torrens to Darlington project, but it’s wrong thinking. The objective should always be to deliver the best value for money, allowing the money saved to be returned to taxpayers or invested in other projects. If invested in other projects, then those projects will create their own jobs, and the end result will be a better road network for the same amount of money spent.

This isn’t to say that tunnels are always the wrong decision, or that we shouldn’t spend a lot of money when it makes sense to do so. Tunnels often do make sense when there is a hill, water body, or very dense urban area in the way, and there isn’t a feasible alternative route that avoids these obstacles. One example in Adelaide is the Heysen Tunnels on the South Eastern Freeway (though the MATS plan proposed an alternative route that would have avoided the need for a tunnel, it would have been longer and less ideal in my opinion). Nevertheless, in cases where good long-term planning and gradual land acquisition could avoid the need for tunnels, we should almost always do that, and save taxpayers some money. While tunnels have some advantages (reduced noise and visual impacts), they also have significant disadvantages (higher construction and maintenance costs, lower speed limits, less convenient entries/exits, limited options for future upgrades, connections or widening, and prohibitions on carriage of dangerous goods). We should never favour tunnels just because they’re “cool”.