The 105th Congress will not overhaul the federal income tax. Nor will it privatize Social Security, restructure Medicare or revamp the regulatory code.

If the last Congress--especially the GOP freshmen -- appeared to approach government cuts with a swagger, the current crop of legislators seems to skulk, hoping to offend no one, especially such noisy organized constituencies as senior citizens, labor unions and environmentalists.

But the House and Senate will pass bills this session. If you want to know whether the Republican-led Congress has any backbone, pay attention to one measure up for reauthorization this session: the federal highway bill.

Called "'Ice Tea,'" the Intermodal Surface Transportation Efficiency Act (Istea) is ripe for reforms consistent with the decentralist approaches that Republicans applaud.

Unglamorous and mind-numbingly technical, this legislation is also riddled with special-interest influence. The interstate highway system is complete, with the only ""unfinished'' portions being intracity beltways that local drivers should finance.

The direction Congress takes as it adopts this bill will clearly signal whether the Republican majority is willing to rebel against the Beltway establishment.

Before deficit reduction became trendy, only reauthorizations of the defense budget rivaled the highway bill in popularity among lawmakers.

Istea is the mother lode of political pork, the bill that has previously funded such projects as recreational motorcycle trails, museums and "demonstration projects'' to relieve traffic congestion in rural counties with fewer than 10,000 residents.

Rep. Bud Shuster, the Pennsylvania Republican who heads the Transportation and Infrastructure Committee, was able to deliver a $35 million commuter-rail stop, a $30 million moving sidewalk and the $286 million Bud Shuster Highway to his hometown of Altoona (population 50,000) when Republicans were still in the minority.

Along with garden-variety pork, federally funded highway projects must conform with a layer of regulations that serve to line the pockets of politically connected contractors and suppliers.

Transportation analyst Gabriel Roth, author of last year's "Roads in a Market Economy," estimates that congressional mandates to buy American-made products and pay "prevailing" (union) wages make federal road projects 28 percent more expensive than necessary.

Robert Poole, president of Reason Foundation, which publishes Reason magazine, notes that the feds often prohibit tolls from being charged on federally funded highways. This prevents experiments with peak-hour pricing and other market-oriented transportation reforms.

Last year, innovative approaches to Istea looked possible. The most promising would have taken the source of about half the federal highway funds, the gasoline tax, out of the congressional pork barrel.

Three Republicans, House Budget Committee Chairman John Kasich of Ohio, Rep. Nick Smith of Michigan and Sen. Connie Mack of Florida, now chairman of the Joint Economic Committee, proposed returning about 80 percent of the 18.4- cent-a-gallon tax to the states.

Their plan would have left only a few pennies per gallon to finance maintenance of the highways already built. But don't hold your breath. Rep.Shuster still chairs the transportation committee, and he has no intention of relinquishing his power base.

Instead of transferring the gasoline tax to the states, he wants to remove the federal highway trust fund (where the gasoline taxes technically flow) from the budgetary process. This would place $15 billion completely in the hands of Bud Shuster and other political bosses.

Rep. Shuster may also be willing to dedicate as much as one-half cent of the gasoline tax for funding Amtrak, providing life support to a hopeless federal boondoggle.

This ploy would give Rep. Shuster an important ally, Amtrak enthusiast William Roth, the Delaware Republican who chairs the Senate Finance Committee.

The highway bill offers a clear test of whether members of Congress will relinquish a bit of their power or will succumb to the temptation -- as Gov. Lepetomaine said in Mel Brooks' "Blazing Saddles"-- to protect their phony-baloney jobs.

For now, bet on the baloney.