More than 51 million

motorists are predicted to hit the roads this season, a 1.7 percent increase from last year, despite higher gas prices, according to the American Automobile Association.

For the legions of folks hitting the highway, travel experts recommend checking weather reports along their routes and rotating drivers to ensure the person at the wheel stays alert.

New Yorker Kamika McLam is among the the 3.2 million traveling by train or bus, and she said she was grateful that the city's transit workers were back on the job.

She took the subway Friday to Penn Station where she planned to catch a train to Washington and spend the holiday with her family.

The subways were a welcome sight, since the strike would have complicated her travel plans.

"I don't know how I would have gotten here this morning," the 25-year-old student said.

A smidgen less than 9 million will travel by air, and for them, there's good news. They can take along their nails clippers and tweezers since the Transportation and Security Administration has amended some safety rules.

However, air travelers will face stepped-up random screenings at airport checkpoints, a security measure meant to dissuade terrorists.

"Doing this is a way of adding unpredictability to the screening process in order to deter terrorist attacks," Transportation Security Administration spokeswoman Jennifer Peppin said Wednesday in a cell-phone interview from Seattle-Tacoma International Airport.

In the past, boarding passes indicated which passengers had been randomly selected by computer for screening. Travelers also attracted additional scrutiny if they set off a metal detector.

Beginning Thursday, passengers and their bags will be subject to more screenings, Peppin said. In most cases the process should take about two minutes, she said, and "we aren't expecting any significant delays at the checkpoints."

Passengers can expedite the process by taking off coats, heavy jackets and shoes.

In addition to passing through a metal detector, passengers should expect "explosives screening of shoes, hand-wanding of passengers, enhanced pat-down searches and inspections of carry-on bags," the TSA warned.

To make things easier, Peppin recommended that travelers remove any large metal items before going through screening points. Gifts should also be left unwrapped to avoid unnecessary inspections, she said, noting that on Wednesday a Christmas present had to be opened after a blender set off an alarm.

Under TSA's plan, passengers also will be allowed to carry on board scissors with a cutting edge of four inches or less and tools such as screwdrivers, wrenches and pliers smaller than seven inches.

Such items make up about one-fourth of the millions of prohibited items confiscated from carry-on bags each year since the September 11, 2001, terrorist attacks. Boxcutters, lighters, knives, ice picks and hammers will continue to be barred.

"By incorporating unpredictability into our procedures and eliminating low-threat items, we can better focus our efforts on stopping individuals that wish to do us harm," Kip Hawley, TSA assistant secretary, said earlier this month in announcing the changes in Washington, D.C.

The changes go into effect as the nation's airlines are in the midst of the busy holiday-travel season. During peak travel days -- Thursday and Tuesday -- 100,000 passengers are expected to go through Seattle-Tacoma International Airport alone. Normally, that number is around 70,000, airport spokesman Bob Parker said.