It came to me finally while rummaging through my various pairs of hiking boots. Torn between the heavy-duty leather models suitable for Everest or the ultralight high-tops perfect for fellwalking, I sat back and came to my senses. A simple pair of walking shoes would do quite nicely for England, since I wasn't likely to take my mother and my aunt anywhere that required something lower than a one-inch heel.

Not that they don't or can't walk around the block. Like most Texans, they do have a distrust of covering distance in other than motorized fashion, but more to the point, since I'm pushing 40, my mother is (forgive me, Mom) elderly and my aunt not far behind. There are certain inescapable facts about reaching the age of 70, and one of them is that if you haven't been much of a walker all those years, you're even less of one now. I put away the hiking boots, and began to wonder what else I had failed to consider in planning my itinerary.

The idea to treat my immediate family -- Mother and my aunt Dorothy -- to a trip abroad was an easy one, and age did have something to do with it. Mother has her health, but several of my friends have recently lost their parents and my own stepfather died a couple of years ago, after failing quite rapidly and unexpectedly. Then I saw my father after a long separation, and I was shocked at his frailty. Intimations of mortality were all around me, and I wanted to give Mother something she'd really enjoy while she could still enjoy it.

Twenty-one years ago my mother and I went to Europe. It was the summer I graduated from high school, and the trip was a whirlwind visit to the great spots, a Grand Tour in the if-it's-Tuesday-this-must-be-Belgium manner. We saw fireworks on the Grand Canal in Venice, snow in July in Germany. I was almost run over by a steamer on Lake Lucerne when I went out too far with a friend in a paddleboat. And somewhere I still have a casino chip picked up in Monte Carlo.

It was a great trip, but it was crowded, since we went nearly everywhere in a pack of Americans. And we were rushed from place to place for six weeks, with hardly a moment for contemplation, something I didn't really miss until I aged a bit. Now I could do for her what she had done for me, take her on a journey and use everything I had become in the 20 years since I'd lived in her care to take care of her.

She chose England, and I suggested the itinerary: a few days in London to see the Chelsea Flower Show, followed by an auto trip through Bath, the heart of England and the Welsh Marches. Two weeks seemed about right for the length of our stay, considering the strain of air travel and the stamina required for sightseeing. Anything less seemed hardly worth the trouble; anything more seemed taxing, not only to financial but physical resources, since it was difficult for me to gauge my mother's abilities.

I tried to think about how our age difference might shape our days, but I was embarrassed to bring it up. You can't exactly say to someone, least of all your mother, "What is it you cannot do?" Diplomacy and imagination are required, and a good memory. Mother thought walking around Mount Vernon was a bit much a few years back; it would be wise, I surmised, not to schedule a lot of schlepping around London. I did check with her directly about some recent surgery, however. What were the doctor's instructions? She said she wasn't supposed to lift heavy items, but that she would be otherwise recovered by the time we left.

I told my husband to work on his biceps, and I cut down on the hiking, but there were still things to learn. Most general travel advice applies to older travelers as well as anyone, but some matters are more significant, like insurance. I found I could check Mother's American Association of Retired Persons health coverage myself through the headquarters here in town.

At the travel bookshop, I looked for information on senior citizens as well as guidebooks. Rochelle Jaffe, who runs Travel Books Unlimited in Bethesda, recommends the AARP's "Travel Easy: The Practical Guide for People over 50" by Rosalind Masson. It's a popular, very general guide with some useful specific tips, like checking for an age maximum if you plan to rent a car. It also has discount listings, for everything from airlines to hotels to British rail.

Most of the general guidebooks have a section on discounts at your destination, and one of Jaffe's other recommendations, an inexpensive little book called "The Travel & Vacation Discount Guide" by Page Palmer, has a very wide-ranging section on breaks for senior citizens. Companies change all the time, however. I found the best policy was always to ask if there was a discount whenever I ordered anything, including theater tickets.

Like many Americans, I suffer acutely from the tourist disease of planning to cram too much into a sightseeing day. I constantly had to modify my itinerary in action. I didn't really put enough breaks in the day, or make the days short enough.

For instance, I couldn't count on how tiring the flower show crowds would be. Mother lasted barely two hours, while I was ready for two days of muscling through fanatical gardeners. So I wrangled up a bus tour of London for her and my aunt, which left them better informed about the sights than I was and far more rested.

Once we rented a car and got out into the countryside, we really hit our stride. We were in control of our day in a way taxis and subways wouldn't permit. (Mother wouldn't ride the tube in London, and the one morning my husband and I set out to do so, there was a record jam downtown that turned the stations into a kind of fluorescent, damp edition of the Black Hole of Calcutta.)

Prowling along country lanes so narrow that the cow parsley and the hedgerows brushed both sides of the car as we passed, we did the least strenuous sort of sightseeing. And I had had the foresight to rent a station wagon with four doors instead of two, an arrangement that made getting into the back seat as easy as possible.

As it turned out, we usually needed our strength for the steep stairs that greeted us every evening in the country house hotels where we stayed. Next time we travel together, I'll inquire about accessibility beforehand. But Mother never complained, even when she had the breath to do so.

The car and the countryside offered maximum flexibility for us. We could pull in at Ragley Hall and feed the peacocks in the yard, we could stop at every ruin and skip scheduled stops that seemed too far after all or too crowded. Anyone who was tired could nap, and those who were finished tramping around Tintern Abbey in a downpour could troop back to the car and read guidebooks and atlases while slowpokes finished up.

Motoring narrowed the generation gap with regard to physical stamina, and always gave us sights to talk about. My mother and I, living a thousand miles apart for 20 years, got reacquainted over tea and scones and clotted cream in the shadow of Wells Cathedral, and walked through the crumbling, windswept galleries of the White Castle in Wales, learning as much about each other as we did about warriors long dead.

As all mothers and daughters do, we had our differences of opinion on occasion, in which I sometimes found myself slipping down that rabbit hole into childhood again. I didn't show my best colors, perhaps, when emotions wore thin on a cold, rainy day in Camden Town (a bit too Bohemian for Mother's taste) or during a crush for tickets at the gates of the flower show. I felt all my good intentions under siege, my gift unraveling under my hand. I had a glimpse, in fact, of what it must have been like for her sometimes, taking my life in hand years ago.

As it turned out, I had few collisions and many successes. Planning a journey for my mother, as much work as it was, was like concocting a surprise party with new prizes and presents unwrapped every day. I got to give the party and enjoy it too. I had a look at my future and a taste of my past. And I'd do it again.

Pat Dowell is a Washington writer who covers movies for The Washingtonian magazine and other publications.