It seems like every major Northwest city has one: a big costly road-expansion project. Seattle has the 520 floating bridge replacement (estimated at maybe $6 billion); Portland has the Columbia River Crossing (pegged at around $4 billion); and Vancouver has the Port Mann Bridge ($3.1 billion).

Each city is talking about steep price tags for dubious projects. These are projects that are likely to increase sprawl and driving—and that may even sap energy from the urban centers. And in each case, it’s hard not to wonder, what else could we do with that much money?

So I thought this piece of analysis was a bit ingenious:

By the time Prof. Patrick Condon and researcher Kari Dow at the UBC Design Centre for Sustainability finished punching in the numbers and mapped their results, they produced a startling alternative vision. For the same money, concluded the team, the government could finance a 200-kilometre light rail network that would place a modern, European-style tram within a 10-minute walk for 80 per cent of all residents in Surrey, White Rock, Langley and the Scott Road district of Delta, while providing a rail connection from Surrey to the new Evergreen line and connecting Pitt Meadows and Maple Ridge into the regional rail system.

So there you have it. For $3.1 billion residents of Greater Vancouver should be able to choose either a) a single new 10 lane bridge, plus road-widening on each side, for a suburban commuter highway; or b) 200 kilometers of light rail stitching together a number of suburbs and towns in the Lower Mainland. Here’s the hypothetical tram map, centered southeast of Vancouver:

port mann

Wouldn’t it be great to see a map like this for Portland and Seattle?

I don’t mean to sound flippant. Whether or not Condon and Dow are exactly right about the cost of light rail and its reach, this is precisely the sort of exercise that should inform transportation planning. Instead of high-stakes zero-sum questions—do you want a billion dollars of new roads or nothing?—citizens should know what else they could do with the money. How many miles of streetcar line can be built for a billion? What would a billion do for express bus service? Or, what does a billion dollars worth of bicycle infrastructure look like?