Q We will be visiting London during the holidays and would like to drive to Paris for the day. Is this possible? I've also been warned about renting a car in London because parking is difficult.

Jamil Shawwa

McLean

A I would not rent a car in London. Not only is parking difficult, but traffic is congested. Also, driving on the opposite side of the road is especially unnerving in a large city.

You could drive to Paris and back in a day via ferry or train, but I wouldn't recommend it. Even without traffic (unlikely), the trip would take about five hours each way, leaving barely any time for sightseeing. The trip by bus takes too long, and flying is impractical because of the time it would take to travel to and from the airports and to get through security.

Taking the train, a three-hour journey, makes the most sense, although it's pricey: The round-trip fare would cost at least $179. Or you could spend a little more and go through a company called Britain Shrinkers, which offers both unescorted and escorted day trips from London to Paris via Eurostar. An unescorted tour includes rail fare and a Paris mass transit pass for $190. An escorted tour, which includes a tour of Paris, starts at $238. The company also offers overnight trips. Info: 011-44-1963-435650, www.britainshrinkers.com.

My niece is getting married next summer in Boulder, Colo., and we'd like to make a two-week vacation out of it with our family of seven, including five children ranging from age 2 to 12. Our children want to swim in the Great Salt Lake, see dinosaur fossils, attend a rodeo, see a ghost town, learn about Native Americans and the early settlers and possibly see the Grand Canyon. How can we limit things, but still get the most out of our trip?

Faith Roberts

Vienna

We Easterners don't easily grasp the huge distances that separate cities and sites out West. Starting from Boulder, if you wanted to see the Grand Canyon and the Great Salt Lake, you'd have to drive 15 hours one way. With five children in the car, I don't think you want to go there.

I'd save the Grand Canyon for another trip and, unless you can fly into Denver and out of Salt Lake City, I'd cut out swimming in the Great Salt Lake.

Dinosaur National Monument (435-789-2115, www.nps.gov/dino), on the border of Colorado and Utah, is a five-hour drive from Boulder. Spend a few days there viewing the dino quarry and enjoying the outdoors, including whitewater rafting: Dinosaur River Expeditions (800-345-RAFT, www.dinoadv.com), for example, offers day trips ($65 for adults, $48 for children 6 to 12, free under age 6).

Then drive three hours southeast to the Aspen area for the Snowmass Village Rodeo (970-923-4433, www.snowmassrodeo.com), which takes place every Wednesday and Saturday from the end of June through August. From there, head 90 minutes east to the Leadville area, which is steeped in early settler history. South Park City in nearby Fairplay is not an authentic ghost town, but it may hold more appeal for the youngsters with its 34 restored buildings. Info: 719-836-2387, www.southparkcity.org.

For more ideas, contact Colorado Travel & Tourism, 800-COLORADO, www.colorado.com.

I suspect that US Airways intentionally canceled my flight from Reagan National to Portland, Maine, due to low passenger load. What are passenger rights in cases like this? Can we go to the FAA and request verification that there was a bona fide equipment failure? If an airline intentionally inconveniences travelers under false conditions, what recourse does a traveler have?

Dan Quigley

Washington

"We don't do that," said David Castelveter, spokesman for US Airways. Castelveter said that planes are carefully scheduled so they can be used for the next flight: "Even when we have a last flight of the day with only a few people, that plane needs to get to that city because it's most likely going out full the first thing the next morning."

Regardless of whether it happened, there are no specific laws prohibiting the cancellation of underbooked flights. But the Department of Transportation could take action against an airline for regulatory violations relating to deceptive trade practices if it could be proven that a flight was deliberately canceled solely for economic reasons, according to Mike Wascom, spokesman for the Air Transport Association, an airline trade organization.

Realistically, however, the chances of DOT taking action against US Airways in this situation are slim to none. Airlines have historically been given a lot of leeway in canceling flights. For example, an airline is allowed to redeploy a plane if another flight develops mechanical problems and more people are booked on that flight, according to Wascom.

Consumer complaints should be filed with the Department of Transportation's Aviation Consumer Protection Division (202-366-2220, http://airconsumer.ost.dot.gov/problems.htm).

Postscript

The Travel section's astute readers were quick to point out several slips in the Nov. 10 Travel Q&A column. Puerto Rico is not a country, it's a commonwealth, and Nova Scotia may be a peninsula, but it's no island.

Send queries by e-mail (travelqa@washpost .com), fax (202-912-3609) or U.S. mail (Travel Q&A, Washington Post Travel Section, 1150 15th St. NW, Washington, D.C. 20071).