Those of us who live in and around Seattle will vote this November on a huge package that’s being sold as "roads and transit." Stay with me — it’s complicated but important, and it could have implications for transit projects around the US.

Of the $18 billion in the package, about $10 billion will pay for 50 miles of new light rail; the rest will pay for roads projects, including 152 new miles of general-purpose highways (and 74 miles of HOV). Because our state legislature, in its infinite wisdom, tied the two unrelated proposals together, rejecting roads means rejecting transit, and vice versa. Pro-transit supporters of the package (and there are lots of them) pretty much stop there. How, they argue, could we turn down the first opportunity we’ve had in a generation to more than double the region’s light rail system? Yes, there are roads in the package — including bad roads, like the four-lane widening of a major suburban freeway — but a lot of those will actually help transit. Expanding SR-520 from Seattle to Bellevue, for  example, will create two new HOV lanes. And look at all that light rail! Shiny, shiny light rail. How could you say no to all that light rail?

Well, let’s look at what happens if this region does pass the joint roads and transit package. That will be our last chance to make a truly ambitious investment in transportation for a generation. It is, in other words, our last chance to do it right. As local Sierra Club chapter chairman Mike O’Brien told me, "It’s not like we have pools of $18 billion just sitting around." If we pass this package, we’ll have light rail, but we’ll also be stuck paying for, and building, all those new roads — roads that will just fill up, as roads do; roads that will contribute more to global warming than light rail takes away; roads that certainly won’t be much help in easing congestion without a much larger investment in transit than the one in this package. And we’ll send a message to transportation planners around the country: "It’s OK to have transit, as long as you throw some new roads in there too."

A better message would be: "People want transit, so why do you keep giving us *$%! roads?"

One thing almost no one is talking about is the climate impact of a massive new investment in road expansion. They should be. Sure, boosters of the proposal pay lip service to reducing greenhouse gases, but when it comes to taking real action on climate change, they’re still completely in the pocket of the pavement lobby. While the plan does include a "study" of the climate impact of the package, it also has strict "accountability" requirements that lock regional leaders into building every single mile of road in the package. So the study doesn’t matter. A little-noticed regional study predicts that all the projects in the proposal get built, greenhouse-gas emissions in the region will increase roughly 43 percent. That’s a lot of emissions for a region that says it cares about melting ice caps and polar bears.

There are other problems with the package. It’s paid for with  regressive sales tax instead of user fees like congestion pricing. Meanwhile, the roads in the package are mostly what enviros would call "bad" roads: massive expansion of suburban freeways, new connections between sprawling exurbs and the region’s already overtaxed interstate, I-5, and a highway that will serve sprawl and pave over some of the last remaining oak prairie in Western Washington.

In an editorial in the Seattle Times, King County Executive (and light rail supporter) Ron Sims wrote that the plan "doesn’t solve traffic congestion in the short term, nor does it provide enough long-term relief to justify the financial and environmental costs. … We must not make transportation decisions without considering the impact on global warming."

He’s right. The roads package we’re being asked to vote on represents the solutions of the past — regressive sales taxes, toll-free general-purpose lanes, and pavement, pavement, pavement — and, in doing so, sells out future generations.