As many will immediately notice, the film bears more than a passing resemblance to John Hughes' 1987 Steve Martin and John Candy vehicle, Planes, Trains and Automobiles. Like Hughes’ semi-classic, Philips’ movie blends both the dialogue heavy, character based odd-couple dynamic and the madcap road-trip genre. As far as the character based comedy goes, the humour lies squarely upon the shoulders of Downey Jr. and Galifianakis. The challenge that Philips gives these two gifted performers is that of crafting their characters’ fairly despicable personalities into ones that the audience can not only just bear, but actively route for throughout the film's 100 minute running time. Fortunately the two actors easily rise to the challenge, with Downey Jr’s witty everyman quickly becoming justifiably exasperated with Galifianakis’ witless, but endearing wannabe actor (whose aspirations stretch as far as to desire a part on the CBS sitcom Two and a Half Men). The ridiculous events and personas are grounded by giving the two leads something real and emotionally complex in which to set their cross-country escapades around; these are quite literally matters of life (the birth of Highman’s child) and death (Tremblay carries with him his departed father’s ashes) that have an obvious through line, each of them perhaps too conveniently dipping in and out of relevance.
However, despite the best intentions of these performances, Philips – who co-wrote the screenplay – puts the characters into numerous situations of questionable decency; at one point Highman alarmingly punches a small child, while Tremblay recklessly endangers the lives of everyone on the highway multiple times. Instances such as these threaten to push the audience away from the protagonists in disgust. The characters are reeled back in, not only through the leads’ charm but also through the constant movement that the road trip setting provides. Philips, obviously having learnt that a little can go a long way, echoes the much talked about cameos in The Hangover with a plethora of recognisable faces. With each one we get new interactions and violent confrontation, as has become standard with the physical nature of the comedy. The film is far from a classic, but with the two stars being at the height of their popularity and Planes, Trains and Automobiles being just past the double-decade anniversary it is a bawdy, amusing but ultimately forgettable trip between Hangovers one and two.