For five days, Paul Theroux, the famous American travel writer, dined on hard-boiled eggs, microwaved dal and wine.

He had set out cross-country in a rented Jeep Compass, driving from Cape Cod, where he has a house, to Los Angeles, where he delivered boxes of his papers to his archives at Huntington Library, then flying to Hawaii, his other home.

Theroux observed a landscape largely emptied out by the coronavirus pandemic, from deserted motels in Tucumcari, New Mexico, where he stopped to sleep, to a rest area in Tennessee, where he had his solitary Thanksgiving meal.

Every night, he wrote out in longhand all he had seen. "It was like a panning shot of America," he said in a video interview.

Theroux turns 80 this month. For a generation of backpackers now gone grey, the tattered paperback accounts of his treks through China, Africa and South America were a prod to adventure, books of inspiration under many a mosquito net.

He has a new novel out from Houghton Mifflin Harcourt this month, Under The Wave At Waimea, and his best-known book, The Mosquito Coast, has been adapted into a television series starring his nephew, Justin Theroux, set to premiere soon.

Paul Theroux does not see himself as anywhere near done. Before Covid-19 struck, he had plans to go to central Africa. He is deep into another novel and finishing a new story collection.

Travel narratives are his signature, a genre he grabbed onto in the early 1970s out of desperation, when as a young novelist with a few books under his belt, he found himself out of ideas.

He decided to traverse part of the world by rail, starting from London, where he was living, through the Middle East and South-east Asia, returning on the Trans-Siberian Railway.

The account that emerged from this tiring journey, The Great Railway Bazaar, has sold more than 1.5 million copies and inspired shelves upon shelves of books built on similar conceits.

In just the past decade, Theroux has written about driving solo through Mexico (he always travels alone) in On The Plain Of Snakes (2019); an exploration of some of the poorest regions of his own country in Deep South (2015); and a trip to Africa, The Last Train To Zona Verde (2013), in which he returned to regions he got to know as a Peace Corps volunteer in the 1960s.

This genre - the outsider arrives and offers an assessment of the foreign - has lost ground over the years to travel memoirs like Elizabeth Gilbert's Eat, Pray, Love (2006) that describe journeys of the internal terrain as much as the people encountered and places seen.

Theroux defended his approach. "It's more necessary than ever to find the empathetic experience of meeting another person, being in another culture, to smell it, to suffer it, to put up with the hardship and the nuisances of travel, all of that matters," he said.

He quoted Nobel Prize-winning author V.S. Naipaul, who at various moments in Theroux's writing career was a mentor and a nemesis: "I believe that the present, accurately seized, foretells the future."

Theroux seems aware of the notion that his way of writing about the world is fading.

His new novel tells the story of Joe Sharkey, an ageing North Shore surfer who resembles characters Theroux has come to know on the beaches near his home.

Sharkey feels acutely that he is being overtaken by younger surfers with big endorsements. For him, surfing was a way of life, an existence centred on catching waves, a commitment to the ocean.

Theroux sees surfing as a metaphor for his own life. All he ever wanted was to be able to write without interruption, without the need to do anything else for money, but sit day after day at his desk.

In many ways, he has achieved this. But like the surfer past his prime, he is not immune to feeling forgotten, to the sense that the world has become hostile to the pure joy of the waves. There is a fear of being overlooked, unread.

"I was once a hot shot. I was once the punk," he said. "And anyone who has once been a punk, eventually you're older and you see the turning of the years as it is. We all feel it, every writer."

Theroux sees advantages in ageing, like the older surfer whose decreased stamina forces him to search for new, smarter ways to ride his board - after all, Theroux points out, it was a man in his late 40s, Mr Garrett McNamara, who surfed the largest recorded wave.

Theroux can see how travelling as an octogenarian will have its assets.

In some cultures, older people are invisible, a benefit in many situations, he said. In other places he has visited, the elderly are treated with respect. "They either jump out of their chair and give it to you or they just ignore you," he said.

And where might he want to go to next?

What he most wants to do is return. There is value in making your way back to a country you visited when you were younger. It both marks time in your life and acts as a sort of gauge for how a society is changing.

"It tells you about the direction of the world," he said. "What's going to happen to the world? And you find that you can extrapolate that by revisiting a place that you knew well.

NYTIMES