When best friends Ewan McGregor and Charley Boorman decided to ride their motorcycles around the world, they worried about the dangers that might lie ahead.

They feared the treacherous roads in Mongolia, the weather in Russia -- even the bears in Canada.

What they didn't expect, however, was for the most terrifying moment of the trip to happen on a calm stretch of Canadian highway just outside of Calgary.

"We drove 20,000 miles (32,000 km) and some 12-year-old kid, who just got his driver's licence, almost kills Ewan as we were literally coming into Calgary," says Boorman from his home in London.

"The traffic had slowed down and this kid just smacked his car into Ewan. How Ewan stayed on and alive, we're still not sure. That was the closest either of us came to being killed."

McGregor, who starred in the latest Star Wars films, and Boorman, who appeared in The Serpent's Kiss, began their quest to circumnavigate the globe in April 2004.

After setting off from London, they chased their shadows through Europe, Russia, Siberia, Kazakhstan, Mongolia, Alaska and across North America to New York.

Long Way Round, a seven-part documentary series which makes its Canadian premier on the Outdoor Life Network on Tuesday, is the result of that journey.

"Until you actually go out and do it, you're just not sure if anything interesting is going to happen," says Boorman. "In the end, it certainly exceeded everything we thought it would be."

During the four-month excursion, McGregor and Boorman, along with one cameraman, were courted by men with large guns in the Ukraine, had their lives threatened in Kazakhstan, suffered from hunger and exhaustion in Siberia, helped fight forest fires in B.C. and took in the Stampede.

"Calgary was a bit of drunken blur," admits Boorman. "The Stampede was on and we hung out in all the bars -- it was brilliant. It's a great, fun place."

While Cowtown may have been a blast, it was a far cry from Mongolia, which Boorman calls the most difficult and most rewarding part of the trip.

"The beauty of Mongolia and the people were so nice, but it was tough," says Boorman. "There was no roads, no sign posts -- it turned out to be everything we wanted from this experience."

Mongolia also presented its share of danger. At one point, the men phoned one of their support vehicles, which became involved in a serious accident during the call.

"It was a terrible, huge crash -- they rolled the car three times. They were only 80 miles (130 km) away, but ... to get to a hospital was a four-day journey," says Boorman, adding it's amazing no one was seriously injured.

"That's when we suddenly realized this wasn't a holiday or a game."

Despite the dangers, Boorman says he and McGregor would do it all over again. In fact, they are currently planning a trip to Africa where they'll do some work for UNICEF.

Actor Jude Law, however, will not be joining them on the trip as reported in British newspapers last week, he says.

"We were laughing about that. Maybe someone thought it would be a good idea for Jude to have a sabbatical, but I don't even think Jude rides a motorbike," laughs Boorman. "But, you know, if Jude wants to come along without a bike, I don't see why not."

Long Way Round airs on the Outdoor Life Network at 7 p.m., 8 p.m. and 11 p.m. Tuesday.