Q: I would like to visit New York City. I assume hotels are cheaper in New Jersey than in New York. Can you recommend New Jersey hotels that are close enough to get into New York using public transportation?

Alex Cohen

Washington

A: If you require a three- or four-star, name-brand hotel to feel comfortable, I agree with your assumption: Those kinds of hotels are cheaper in New Jersey. A stay at the Doubletree, for example, will cost $259 a night in Manhattan, but across the river in Jersey City just two blocks from a PATH train station, you can get a Doubletree suite with a kitchenette for $169.

But if you're willing to park yourself at a generic, tourist-class hotel, you can get a room in Manhattan for the same price, or even cheaper, than a room in Jersey. Some good economy choices in Manhattan include Hotel Riverside (212-724-6100) on the west side of Central Park at 88th Street, with rooms starting at $110 a night; the Hotel Newton (212-678-6500) on Broadway between 94th and 95th, with rooms starting at $99 a night; and the Gershwin Hotel (212-545-8000) on 27th Street, just off Fifth Avenue, with rooms starting at $99 a night. Several Internet sites, including www.quikbook.com and www.hoteldiscounts.com, offer good deals on hotels in Manhattan, but make sure you shop around. For example, a room at the Sheraton Manhattan, a three-star hotel in Midtown, was recently offered for $140 a night on www.quikbook.com, while the same hotel on the same dates was renting for $189.95 on www.hoteldiscounts.com.

If you're still stuck on Jersey, there are several hotels in Secaucus adjacent to a bus line that goes directly to the New York Port Authority; the cheapest, the Holiday Inn, costs $129 a night on weekends, $159 weekdays. The Ramada Plaza Suite Hotel and the Sheraton Suites at Lincoln Harbor on the Hudson River are adjacent to a ferry that provides service to Midtown, but rooms cost upward of $120 a night. Several hotels near Newark Airport have rates of less than $100 a night, but none are very convenient to public transportation into Manhattan.

Q: I would like to spend 10 days in the Italian or Swiss Alps and hike every day for five or six hours with a group of people. Could you suggest an organization that can provide information?

Jaroslava Bloomberg

Arlington

A: Here are a few choices:

Ramblers Holidays, an England-based company that has specialized in walking vacations for 52 years, has several tours. A week-long "Mountain Walking From Limone" tour, for example, costs about $800 for a single traveler, including air fare from London. A brochure costs $3 for postage and can be ordered at www.ramblersholidays.co.uk or by faxing 011-44-1707-333-276.

Distant Journeys, a Maine company run by Outward Bound instructors, offers varied tours throughout the Alps. A 12-day, hut-to-hut hike across France, Italy and Switzerland costs about $1,950; air fare is not included. Information: 1-888-845-5781, www .distantjourneys.com.

Ryder-Walker Alpine Adventures, based in Telluride, Colo., offers slightly more upscale trips through the Alps. An eight-day, inn-to-inn hiking tour of the Alps, with such niceties as luggage transport, costs about $2,000. Information: 1-888-586-8365, www .ryderwalker.com.

Q: We are concerned about a January trip to Costa Rica that our daughter and three or four other young ladies, all in their late twenties, are contemplating. We would like to hear your thoughts about safety for this unescorted group. Can you suggest safer alternatives?

J.M. Jaffa

Potomac

A: According to the U.S. State Department, your concerns may be justified. "Crime is increasing, and tourists as well as the local populace are frequent victims," says the State Department's Consular Information Sheet on Costa Rica. "Most crimes are nonviolent . . . but criminals have shown a greater willingness to use violence in recent years." One U.S. citizen was killed in October 1997 during a robbery attempt, and seven U.S. women have been sexually assaulted at beach resorts since 1995.

That said, when you consider that upward of a half-million tourists visit Costa Rica each year, your daughter's odds of coming home safe and sound are very good. Because your daughter and her friends have nearly three decades of living behind them, I assume they share a bit of common sense--the usual don't-leave-valuables-in-your-car, don't-wander-the-streets-at-night, don't-go-off-without-a-buddy, don't-take-taxi-rides-from-unmarked-cars stuff. So I'd recommend that they make the trip, but with a few caveats. They should stay at a reputable resort or lodge, even if they have to spend a few extra dollars. Or, better yet, go with an organized and escorted tour.

Tour operator choices include Way to Go Costa Rica (1-800-835-1223, www.waytogocostarica .com), a travel agency based in North Carolina that can put together an itinerary including hotel and tour options; adventure specialists Serendipity Adventures (1-800-635-2325, www.serendipityadventures.com) and Overseas Adventure Travel (1-800-873-5628, www.oattravel.com); and ecotour specialist Natural Habitat Adventure (1-800-543-8917, www .nathab.com).

Q: What exactly is turbulence? What causes it? Does it occur more frequently now than in years past? How dangerous is it?

Clarence Drew

Richmond

A: While turbulence alone rarely leads to a crash, it is the leading cause of passenger injuries in nonfatal accidents. As part of its "Turbulence Happens" public education campaign, the Federal Aviation Administration released a bunch of statistics that basically conclude that, while your chances of getting injured by turbulence are slim to none, they're infinitesimal if you keep your seat belt on whenever you're seated. From 1981 through 1997, 73 of the 80 passengers who were seriously injured by turbulence were not wearing their seat belts when the sign was illuminated.

As for predicting when turbulence is going to rear its head, that's tougher. Great minds have devoted lifetimes to figuring out turbulence. Stanford University even has a "Center for Turbulence Research." Parviz Moin, director of the center, took a look at your questions and had this to say: There's no evidence that turbulence occurs any more frequently today than in the past; it's more common in lower altitudes and, at those lower altitudes, more frequent over land; it cannot be detected by radar. If you need more data about the phenomenon, take a look at "Taking Turbulence With Supercomputers," an article co-authored by Moin in the January 1997 Scientific American. On the Internet, www.sciam.com/0197 issue/0197moin.html.

Bottom line: Buckle up, even when the seat belt sign is turned off, and stop worrying. Send queries by e-mail (travelqa@washpost.com), fax (202-334-1069) or U.S. mail (Travel Q&A, Washington Post Travel Section, 1150 15th St. NW, Washington, D.C. 20071). Include your name, town--very important!--and phone number. We can't offer individual replies, but we'll answer as many questions as possible in print each week.