The driver of a delivery van on the outskirts of Maidenhead winds down his window and flaps his arms excitedly as he spots a diminutive woman vigorously pedalling a tandem bike.
"Are you Jane? Aren't you cycling to Leeds? I think you're fantastic," he shouts across the morning traffic.
Jane Tomlinson, 40, smiles and waves at the incredulous driver as she moves into the final stages of her 2,000-mile bike journey from Rome to her home in Leeds.
She has been accompanied by her brother Luke Goward, 39, and The Independent joined the pair yesterday on the 48-mile stretch from Hayes in wets London to Oxford, three days before they reach their final destination. They are due to arrive in Leeds on Monday where they end an expedition that has taken 35 days and covered some of the most difficult terrain in Europe.
Diagnosed with incurable metastatic breast cancer in 2000 and given only months to live, Mrs Tomlinson has defied medical expectation and, with three marathons and a triathlon under her belt, has accomplished extraordinary physical feats in the past two years to raise money for her charity Jane's Appeal.
Having cycled 1,600 miles, conquered the ultimate cycling challenge - the 6,265-feet high Mont Ventoux in Italy - and scrambled through the most testing gorges on the continent, the siblings were nonchalant about yesterday's journey that took in the Chiltern Hills.
"It's like a day off today," jokes Mr Goward.
Despite her illness, Mrs Tomlinson has managed to navigate the complicated route and cycle at an average speed of 12 to 25mph. "We're just tootling along today, taking in the scenery," says Mrs Tomlinson. Their bike gradually becomes a distant dot on the horizon.
Their food breaks are short and regimented - only 20 minute interludes are taken on the three-and-a-half hour trek.
Fundraising, Mrs Tomlinson says, has become an essential life work. And neither she nor her family - husband Mike, 43, and children Suzanne, 18, Rebecca, 16, and Steven, seven - have any idea how long that work will go on for.
She has raised £118,000 for her four chosen charities - Hannah House, a care home in Rothwell, Leeds, Macmillan Cancer Relief, the Paediatric Acute Services and SPARKS (Sport Aiding medical Research for Kids) - in 30 days. Her overall fund-raising efforts have exceeded £450,000.
But the trip has had a profound emotional resonance too and she says it helps her manage her cancer. "It's a big adventure for me," she says. "My future has been taken away from me by my illness. It's really hard to stay positive and to be motivated. That is what I am working towards. This is hard work but it does motivate me.
"I might not get promoted at work [she is a paediatric radiographer] and I might not see my daughter finish university but this is something I can work towards."
She concedes the journey has been wearing - mentally and physically - not least because she has been bombarded by press attention. The pair have a rigorous daily regimen. They get up at 7am and cycle up to 70 miles a day after which they wash their lycra kits before turning in at 9pm. With only four days of rest on this expedition Mrs Tomlinson is looking forward to the end.
Nevertheless it has bonded her to her brother and provided some important memories for him and for her family.
"It is very easy with the illness to think 'It's not fair' but that doesn't change anything. It is not very fair but at least I can enjoy the time with my family.
"The family will have some fantastic memories from this. Luke will have some fantastic memories from this," she says.
Although the adventure has been exhilarating and she has taken in some of Europe's most pristine scenery ("The waters in the canals of southern France are electric blue and really, really pretty," she says. "They are so clear you can see the fish swimming in them."), this is to be her last major long-distance journey. Her role as a wife and mother and a radiologist who is surviving with cancer must now take priority, she says.
"This is the final project. I have worked very hard for two-and-a-half years. I need to make the balance right for my family. I return to Leeds on Monday and I'm back to work that week," she says.
To donate to Jane's appeal telephone 0845 1200829.Reuse content