Based on the British television series of the same name, director Michael Winterbottom’s The Trip finds Steve Coogan and Rob Brydon again playing loose, bickering versions of themselves, uneasy partners on a restaurant-tasting road trip across the British countryside. After some contretemps with his girlfriend, Coogan is left without a partner for his weeklong foodie vacation, so he begrudgingly invites his actor pal Brydon. They then proceed to preen for attention, and spar in competitive, passive-aggressive fashion.

Largely improvised, The Trip is an example of something that probably works a lot better in its short-form incarnation, as an exploration of the cresting nature of comedic riffing. There are moments of pure, unadulterated delight here, in Coogan and Brydon’s arguments over Michael Sheen, or the latter’s hilarious impression of Michael Caine, even modulated to take aging into account. Other impersonations, like the guys’ dueling James Bonds or Woody Allens, are also funny. But the whole is far less than the sum of its parts, and the framework upon which it hangs — which purports to also tangentially assay the insecurity of actors — creaks under the weight of injudicious oversight by Winterbottom and editor Mags Arnold, who overindulge their stars. Like almost any journey, there are a few interesting sights along the way, but this Trip is too long and winding — a scenic route that becomes tedious. (IFC Films, PG-13, 107 minutes)