After the outstanding progress shown by automakers during this year's Detroit Auto Show, you'd think that car travel in this country was entering a new era. But a vocal segment of the environmental lobby is threatening to undermine the future of automobiles by protesting the inclusion of massive road funding earmarks in Obama's economic stimulus package.  "New roads=new pollution," their saying runs.

But honestly, I just don't think all roads lead to bad results—and this is coming from a guy whose daily commute involves half-an-hour of dodging box trucks on a 20-pound bike. Yes, new roadways do promote more car travel, but pressure from the government, tax incentives, and market forces will likely mean that within five years, zero-emission or hybrid vehicles will be available to most folks who want them.  And with the prospect of higher taxes and five-dollar gas for those still clinging to internal combustion alone, I can't imagine the demand will be light.

Even if the throb of carbon-spewing cylinders remains the norm on the nation's roadways, reinvestment in road infrastructure will decrease—not increase—the carbon emissions tied to the Interstate Highway System.  Newly constructed bridges and tunnels will streamline travel and uncork inefficient bumper-to-bumper bottlenecks that waste gas. Redesigned and repaired highways will reduce gridlock, accidents, and carbon emissions through better road surfaces, realigned routes and improved signage. New highway projects will incorporate environmentally-friendly measures like dedicated rapid transit right-of-ways, HOV lanes, and quickchange concrete barriers.

Many working against highway packages in stimulus legislation see the very asphalt of the roads themselves as surrender to the industrial lobby.  After all, asphalt is made largely from oil; it creates oil vapor and run-off pollution and its darker color absorbs sunlight and increases the temperature in urban areas substantially. The surface also wears out in bits and pieces, creating a constant need for more of the material.

But the simple fact is, roads don't need to be asphalt. Concrete surfaces, which wear longer, reflect light, create less noise, and are recyclable, already cap roadways across America. In urban centers, brick and cobblestone surfaces slow traffic, create a more pedestrian friendly environment, and bring a unique aesthetic appeal.

Most importantly, roadways provide an important source of revenue, especially in areas where car-related air pollution is greatest. Toll roads not only decrease congestion by incentivizing commuters to find other means of transport, but they bring in substantial amounts of revenue, much of which goes to fund mass transit, bike lanes, and other  projects encouraging non-automotive travel.

So while paving every inch of America is certainly not in the national interest, road improvement should—and indeed, must—be part of any green stimulus package.  Reducing the environmental impact of our vehicles will only get us so far unless we also minimize the impact of the highway infrastructure we drive on.