It was a long road indeed to U.S. distribution for “On the Road,” but on the eve of Cannes, the trip is finally over: AMC Networks has acquired all U.S. distrib rights to Walter Salles’ adaptation of the Beat Generation tome by Jack Kerouac, to be released jointly by the company’s film distribution labels IFC Films and Sundance Selects sometime this fall.Sundance Selects/IFC Films plans a traditional theatrical roll-out, and will handle all downstream platforms. Starring Kristen Stewart, Garrett Hedlund, Sam Riley and Kirsten Dunst, “On the Road” will world premiere in competition at the Cannes Film Festival, which starts next week. “We are over the moon ecstatic to be involved with this incredible film,” Sundance Selects/IFC Films prexy Jonathan Sehring told Variety. The pickup is “a statement not only to our entire organization’s love of the project, but to the number of different innovative ways we are going to make sure the film reaches as wide an audience as possible.” Said to be in the low seven figures, deal represents the largest acquisition yet for Sundance/IFC. Parent company AMC Networks plans to use all its platforms — including cablers AMC, We TV and Sundance Channel — to promote the pic. Based on a screenplay by Jose Rivera, the MK2 Production was produced by Nathanael Karmitz, Charles Gillibert, Rebecca Yeldham and Roman Coppola for American Zoetrope. Executive producer is Francis Ford Coppola, who bought rights to “On the Road” in 1980. Cinetic repped the U.S. distrib deal that took months to come together, with several bidders in the mix. A buyers’ screening in late February failed to attract a high-profile distributor, which may have had as much to do with the asking price (rumored to be high seven figures) as Salles’ artsy approach to the difficult-to-adapt book. Multiple people who have seen the film agreed that it contains noteworthy performances and cinematography, but add that its two-hours-plus length and nebulous narrative make it a challenge to market to mainstream auds. But “On the Road” has more than one built-in fanbase; Kerouac fans will be eager to check out the “On the Road’s” first-ever bigscreen adaptation. And “Twilight” devotees have been constantly buzzing about Stewart’s role as Mary Lou since the $25 million project was announced two years ago almost to the day. The $25 million pic was shot in late 2010 in New Orleans, Montreal, Mexico and Argentina. MK2, which is repping foreign sales, has already peddled “On the Road” in several offshore territories, with more deals expected on the Croisette.