Forty years ago, actor Peter Fonda flew down America's highways on a motorcycle in counterculture classic Easy Rider. So what better way to celebrate the film's anniversary than with a bunch of bikers?

On Friday, Fonda motored into the Southern California city of Glendale for an annual motorbike event called Love Ride where Easy Rider would be shown in an outdoor screening.

Fonda, the son of legendary actor Henry Fonda, has been part of the Love Ride for more than 25 years, as it grew from a few bikers to thousands motoring up the freeway.

This year, the formal ride was canceled as the poor economy depressed turnout, so the Easy Rider screening became the main reason for participants to gather at a Harley-Davidson shop for a scaled-down event.

Speaking by phone before the screening, Fonda told Reuters Easy Rider, which sees a 40th anniversary DVD edition hit retail stores this month, is still relevant today because many of the social problems it highlights persist.

One of the most famous parts of Easy Rider comes at the movie's end when Fonda's motorbiking character Wyatt tells riding buddy Billy, We blew it.

People often ask me, 'Do I still feel the movie is relevant?' Fonda said. And my answer to them is, when ... I say, 'We blew it,' if you look out the window today and you say we haven't blown it, (then) I don't want to take whatever drug you're on, he said.

The line, uttered cryptically after the drug addled Wyatt and Billy made a bundle of cash in a cocaine deal and ventured to New Orleans, has been interpreted in different ways by movie pundits, but critics have praised its simple summation of the two main characters' journey.

While Easy Rider is a product of the 1960s, Fonda noted the racism and violence that Easy Rider exposed is still a problem in the United States.

The movie has been included in the U.S. National Film Registry, and it ushered in a gritty filmmaking style that has been called the New Hollywood movement for the challenge it posed to the movie industry's decades old studio system with it's look and feel of an independently-made film.

In the years since Easy Rider's release, its three main stars, Fonda, Dennis Hopper and Jack Nicholson have all enjoyed storied Hollywood careers.

Fonda was nominated for an Oscar for his role in 1997 film Ulee's Gold. Hopper, who directed and co-wrote Easy Rider and played Billy, starred in the 1986 cult classic Blue Velvet and has recently appeared in a number of retirement advertisements aimed at baby boomers that play on his iconic status from Easy Rider.

Nicholson has won three Oscars, and most recently starred in movies The Departed and The Bucket List.