Editor’s note: We’re pleased to welcome Kira Marchanese to the Green Options blog! Kira, Director of Internet Communications at Environmental Defense, will be taking over for Jessica Bosanko, who’s moving on to other pursuits, including a wonderful-sounding trip with her partner to South America. We’re glad to have Kira on board, and very grateful to Jessica for her time and effort in contributing to Green Options.

Today’s post is by Tom Elson, from Environmental Defense’s Living Cities program.

If you spend time in a dense urban area like New York City, you know the frustrations of gridlocked streets: blocked intersections, horns blaring and tempers flaring. But there’s an invisible cost to traffic, too: the damaging health effects from breathing the air polluted by so many cars and trucks. Vehicles stuck in stop-and-go traffic produce up to three times the pollution of cars moving steadily.

But New York and other metro areas are on the road to clearer streets and clean air. Congestion pricing is one of the innovations that will help them get there.

The idea is simple: at times when the roads are busiest, drivers pay a premium to use them. Think of the way you buy an airline ticket. When you check fares, you get a wide range of prices depending on factors like when you want to fly and how many stops you’re willing to make. We know that flying at convenient times costs more, and we might take a red-eye to save money.

The concept is the same on the road. An electronic toll system collects the fee as drivers enter busiest sections. The system charges drivers more during the busiest times. Those who take mass transit or reschedule their trip can save money. (See more about congestion pricing.)

This isn’t a new idea. London started charging motorists to enter its central business district in 2003 and has seen traffic congestion cut by nearly a third. Sooty particles and nitrogen oxide pollution dropped by roughly a fifth each. Singapore, Stockholm and several cities in Norway have also reduced traffic, travel time and pollution.

The idea is still new enough in this country to raise questions, though, as last week’s debate in New York shows. Critics of congestion pricing worry that boundary neighborhoods – those just outside the pricing zone — will see an increase in traffic and cars trying to park there. Studies in London and Stockholm show otherwise. Those cities limited conflicts around the boundaries by issuing residential parking permits and creating park-and-ride facilities.

Commuters who live in areas with poor public transit fear not being able to drive – but revenue from collecting tolls is generally used to improve transportation. London, for example, raised hundreds of millions of dollars, which it invested in better transit such as new buses. Ridership rose dramatically, and bicycling increased. There, as in other places that have tried this system, skepticism gave way to enthusiastic support for the plan.

This year Mayor Michael Bloomberg embraced congestion pricing and unrolled a plan as part of his sustainability ‘greenprint’ for New York. A remarkably broad coalition of 140 civic, religious, health, business, labor and environmental groups supported the plan, despite strong opposition from some legislators. After intense negotiations, Bloomberg and state leaders agreed to consider a three-year pilot program.

New York City is one of nine finalists for $1.2 billion in federal grants to try congestion pricing and other traffic-busting incentives. Eight other cites — Atlanta, Dallas/Ft. Worth, Denver, Miami, Minneapolis, San Diego, San Francisco and Seattle — are vying for funds by proposing a variety of traffic-reducing tools, from tolling and parking management to express buses to telecommuting support. New York’s is the most comprehensive, with specific traffic-reduction goals leading to substantial cuts in air pollution and real public health benefits.

You can help! If you live in one of the cities trying to implement smart traffic policies, contact your elected officials and ask them to support congestion pricing.