Singapore, London and other European cities use this strategy to discourage motorists from driving into town during rush hour. The Republican mayor wants to charge an estimated US$8 fee as one of three funding sources for a new agency that will spend US$30 billion on regional transportation.

The new city-led Sustainable Mobility and Regional Transportation Financing Authority would provide half the funding for new infrastructure and the full cost of deferred maintenance, according to a statement from a mayoral spokesman.

Among the new projects the agency may fund is the US$7 billion Hudson River tunnel, according to the spokesman, John Gallagher.

The other US$20 billion for the agency would come from sources that already exist, such as federal grants, said Gallagher, adding US$13 billion of that already was promised.

Gallagher was not available to offer other details -- from how the agency would work with the state mass transit agency to improve commuter lines or whether it will sell tax-free debt.

Many of Bloomberg's proposals will require the state to relinquish some of its control. Democratic Assembly Richard Brodsky, who helps oversee state authorities, said he was again introducing a bill to ban congestion pricing.

"While there is much to admire in the mayor's plan, these fees will, for the first time, make public streets accessible based on ability to pay. That is not acceptable," he said.

Bloomberg already has gathered 70 business and civic groups to help him achieve his goal of slicing global warming emissions by more than 30 percent by 2030.

One business backer, the Partnership for New York City, urged Bloomberg to meet an April 30 federal deadline for applying for new aid that obliges the recipient to try congestion pricing.

The Democratic governor, whose approval ratings have started to rebound after dipping when critics said the new US$121 billion state budget was much too big, told reporters he also wanted to boost mass transportation and ease congestion.

However, Spitzer clearly favored his own energy plan to cut energy demand 15 percent from an expected surge by 2015. "The proposals I made ... are the ones we are pushing right now," he said.

Though Spitzer said he also wanted to slash traffic and find more funds for mass transportation, he added: "We are looking at these proposals, and we'll see what they mean, how they play out. They're complicated. It will take some time."

Both Spitzer and Bloomberg want developers to slash the amount of energy new buildings use, but Bloomberg's plan was much more sweeping, perhaps because he says the city's electric bill will rise US$3 billion by 2015 without stiff measures.

The mayor's proposals ranged from using what he called "creative financing" to boost solar energy in city buildings to stopping sewage plants from releasing methane to getting 2,000 to 3,000 of extra mega watts from new plants or repowering old ones.

The city for years has fended off federal concerns over whether it needs a new billion-dollar water filtration plant, and Bloomberg also proposed a new ultraviolet disinfection system for water drawn from the Catskill Mountains and Delaware River region.