How does congestion toll pricing, used in some cities around the world, cut down on vehicle traffic and promote green-friendly public transit?

-- Bill Higley, via e-mail

Despite increasing green awareness and steadily rising gasoline prices, Americans and other denizens of the developed world -- not to mention millions of new Chinese and Indian drivers hitting the road every week -- are loath to give up the freedom and privacy of their personal automobiles. But snarled traffic, longer commute times and rising pollution levels have given city transportation planners new ammunition in their efforts to encourage the use of clean, energy-efficient public transit. One of the newest tools in their arsenal is so-called congestion pricing (also called variable toll pricing), whereby cars and trucks are hit with higher tolls if they access central urban areas at traditionally congested times.

Singapore was the world's first major city to employ congestion pricing in 1975 when it began charging drivers $3 to bring their vehicles into the city's central business district. The system has since expanded citywide, with toll rates at several locations changing over the course of a day. Funds generated by the program have allowed Singapore to expand and improve public transit and keep traffic at an optimal flow. Some of the tangible benefits of the program, according to Environmental Defense, include a 45 percent traffic reduction, a 10 miles-per-hour increase in average driving speed, 25 percent fewer accidents, 176,000 fewer pounds of carbon dioxide (CO2) emitted, and a 20 percent increase in public transit usage.

London implemented a similar plan in 2003 that was so successful it was extended to some outlying parts of the city in 2007. Today, drivers pay $13 to bring their vehicles into certain sections of London during peak traffic hours. According to the Victoria Transport Policy Institute, London's plan has significantly reduced traffic, improved bus service and generated substantial revenues. Environmental Defense says the plan reduced congestion by 30 percent, increased traffic speed by 37 percent, removed 12 percent of pollutants from the air and cut fuel consumption and CO2 emissions by 20 percent.

A 2006 congestion pricing experiment in Stockholm produced similar results, shrinking commute times significantly, reducing pollution noticeably and increasing public transit use during a seven-month test. The day after the trial ended, traffic jams reappeared, so Stockholm voters passed a referendum to reinstate the plan. Today the city has one of the most extensive congestion pricing systems in the world.

Perhaps the next major city to implement congestion pricing will be New York, if Mayor Michael Bloomberg gets his way. In July 2007, the state legislature rejected Bloomberg's first such proposal -- which would have used funds collected to pay for expansions and improvements to the regional public transit system -- but ever-increasing congestion and pollution might force lawmakers' hand in the future.

"A congestion pricing plan is the most cost-effective way to jump-start transit improvements and reduce traffic congestion," says Wiley Norvell of Transportation Alternatives, one of a handful of groups working with Bloomberg to craft a version of the plan that will fly with state lawmakers. With two-thirds of New Yorkers opposed, it looks like an uphill battle for now, but advocates say passing such rules is inevitable.

CONTACTS: Environmental Defense, www.environmentaldefense.org; Transportation Alternatives, www.transalt.org

I've read that plastic bottles are not always safe to reuse over and over as harmful chemicals can leach out into the contents. I'm wondering if the same issues plague Tupperware and other similar plastic food storage containers.

-- Sylvie, Dawson City, Yukon, Canada

The recent hubbub over plastic containers leaching chemicals into food and drinks has cast a pall over all kinds of plastics that come into contact with what we ingest, whether deserved or not. Some conscientious consumers are forsaking all plastics entirely out of health concerns. But while it is true that exposure to certain chemicals found in some plastics has been linked to various human health problems (especially certain types of cancer and reproductive disorders), only a small percentage of plastics contain them.

According to The Green Guide, a website and magazine devoted to greener living and owned by the National Geographic Society, the safest plastics for repeated use in storing food are made from high-density polyethylene (HDPE, or plastic No. 2), low-density polyethylene (LDPE, or plastic No. 4) and polypropylene (PP, or plastic No. 5). Most Tupperware products are made of LDPE or PP, and as such are considered safe for repeated use storing food items and cycling through the dishwasher. Most food storage products from Glad, Hefty, Ziploc and Saran also pass The Green Guide's muster for health safety.

But consumers should be aware of more than just a few "safe" brands, as most companies make several product lines featuring different types of plastics. While the vast majority of Tupperware products are considered safe, for example, some of its food storage containers use polycarbonate (plastic No. 7), which has been shown to leach the harmful hormone-disrupting chemical Bisphenol A (BPA) into food items after repeated uses. Consumers concerned about such risks might want to avoid the following polycarbonate-based Tupperware products: the Rock 'N Serve microwave line, the Meals-in-Minutes Microsteamer, the "Elegant" Serving Line, the TupperCare baby bottle, the Pizza Keep' N Heat container, and the Table Collection (the last three are no longer made but might still be kicking around your kitchen).

Beyond BPA, other chemicals can be found in various food storage containers. Containers made out of polyethylene terephthalate (PET or PETE, or plastic No. 1) -- such as most soda bottles -- are OK to use once, but can leach carcinogenic, hormone-disrupting phthalates when used over and over again. Also, many deli items come wrapped in plastic made from polyvinyl chloride (PVC, or plastic No. 3), which can leach cancer-causing dioxins. Swapping foods out of such wraps once the groceries are at home is advisable.

Containers made of polystyrene (PS, or plastic No. 6, also known as Styrofoam) can also be dangerous, as its base component, styrene, has been associated with skin, eye and respiratory irritation, depression, fatigue, compromised kidney function, and central nervous system damage. Take-out restaurant orders often come in polystyrene containers, which also should be emptied into safer containers once you get them home.

If your head is spinning and you can't bear to examine the bottom of yet another plastic food storage container for its recycling number, go with glass. Pyrex, for instance, does not contain chemicals that can leach into food. Of course, such items can break into glass shards if dropped. But most consumers would gladly trade the risk of chemical contamination for the risk of breakage any day.

CONTACTS: The Green Guide, www.thegreenguide.com; Tupperware, www.tupperware.com.

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