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.

A lot of the debate around whether the package is good or bad, environmentally speaking, has centered around whether the roads part of the package (known as the Regional Transportation Investment District, or RTID) consists mostly of "good" or "bad" roads. There are a lot of elements to this debate, the first of which is: What constitutes a "good" road? Are new HOV lanes "good" (because they serve people who are carpooling) or "bad" (because they’re still new road miles), and could they have been created by converting preexisting general-purpose lanes to HOV lanes?

Another issue is whether roads that are designated primarily for freight, but can be used by single-occupancy cars, count as "good" or "bad." Further confusing matters is the question of whether already-clogged roads produce more or fewer greenhouse gases when they’re expanded to accommodate more traffic, because traffic moves more smoothly (at least for a little while.)

Given all those variables, it’s not surprising that Seattle’s environmental community is split on whether RTID/Sound Transit is a good or a bad thing.

On the pro side: mainstream enviros like the Transportation Choices Coalition, who argue that most of the roads in RTID are "good," because they include lots of new HOV lanes and freight capacity. By the TCC’s calculation, only 15 percent of the entire joint roads and transit package, or about $2.6 billion, is made up of "bad" roads; according to their analysis, "good" roads make up about 23 percent, or just over $4 billion.

On the other side are environmental purists like (no, really) the local chapter of the Sierra Club, whose own analysis places the percentage of "good" roads at around 8 percent of the entire roads/transit package, or about $1.4 billion, and "bad" roads at around 30 percent, or $5.2 billion.

The primary difference between the Sierra Club’s and TCC’s numbers is that TCC included two expensive road expansions — the extension of SR 167 between Puyallup and the Port of Tacoma, and the proposed new six-lane bridge across SR-520 between Seattle and Bellevue — among their "good" roads. The 520 proposal is controversial because, under the most likely scenario, it would remove 2.3 acres of Seattle’s Arboretum (and include more columns and ramps through the nature preserve) and destroy much of Marsh Island, a wetland near the University of Washington. (In addition, it keeps the number of general-purpose lanes the same, which some argue is hardly an "green" alternative.) Extending 167 is controversial in some circles because there’s no guarantee it would only be used for freight; according to the Sierra Club’s Mike O’Brien, "our concern is, is this corridor going to fill up with new development?"

The larger debate, of course, comes down to whether enviros should stomach a ton of new roads in exchange for transit. The argument for: Sound Transit is shackled to RTID, and if both fail, it’ll be at least 2009 before Sound Transit is on the ballot again. (Washington Gov. Christine Gregoire seems not to recognize that high Democratic turnout in 2008 equals high King County turnout for Gregoire and transit.) And since transit projects historically have not come back to the ballot a second time larger than the first, this is probably our only chance to get 50 miles of light rail. Given that, it’s worth it to bite the bullet and vote for roads.

The argument against: Building new road capacity cancels out the environmental and climate benefits of building new transit; given that our region’s goal is to reduce greenhouse gases 80 percent by 2050, roads expansion shouldn’t be a priority. Additionally, Sound Transit will be so politically popular once it opens in mid-2009, passing a large expansion a few months later will be a no-brainer. After all, the entire mainstream political establishment in Seattle said a new freeway on the downtown waterfront was "inevitable"; they were wrong, and we’re now moving toward a surface/transit option to replace the Alaskan Way Viaduct instead. Conventional wisdom could be equally wrong here.

Personally, I haven’t decided where I come down on this one. Ideologically, I side with the Sierra Club: We should not be spending a single penny (given what we know in 2007) expanding roads for single-occupancy cars — especially not suburban freeways like I-405, which would get two new general-purpose lanes in each direction. The political will for transit will only grow as climate change becomes accepted as a reality.

Pragmatically, I side with TCC: I don’t want to see light rail sacrificed on the altar of ideological purity. If they’re right, and a 2009 light-rail package would end up smaller and less region-wide than the current Sound Transit II proposal. And maybe some of those roads (like 405 and the controversial Cross Base Highway in Pierce County, south of Seattle) won’t end up getting built anyway; if greens are right about climate change becoming orthodoxy, roads expansion will start to look much less appealing (and much more vulnerable to lawsuits.)

It’s a tough decision.