Due Date

Starring: Robert Downey Jr., Zach Galifianakis, Michelle Monaghan
Directed by: Todd Phillips (“The Hangover”)
Written by: Alan R. Cohen (TV’s “King of the Hill”), Alan Freedland (TV’s “King of the Hill”), Adam Sztykiel (“Made of Honor”), Todd Phillips (“Old School”)

We’ll give overrated director Todd Phillips (“The Hangover,” “School for Scoundrels”) the benefit of the doubt and say his new comedy “Due Date” is a homage to 1987’s John Hughes classic “Planes, Trains and Automobiles” and not just a raunchy rip-off. With that said, “Due Date” isn’t a lot of other things as well, primarily funny.

Yes, there are amusing moments in “Due Date.” It would be impossible to go through an entire feature film without laughing at something “Hangover” scene-stealer Zach Galifianakis does or without enjoying the darker comic situations conveyed through yet another of Robert Downey Jr.’s cynical characters.

But overall, the odd pairing of Downey Jr. and Galifianakis is far from enough. “Due Date” is nothing more than a barrel-full of cheap and obvious jokes that will hit with mainstream audiences who think the bearded one can do no wrong.

In “Due Date,” Peter Highman (Downey Jr.) is forced to travel cross country with aspiring actor Ethan Tremblay (Galifianakis) when the two are somehow put on the no-fly list after a ridiculous scenario at the airport with Homeland Security.

Although he is worried he won’t make it from Atlanta to L.A. to witness the birth of his first child, high-strung Peter takes his chances with Ethan, a slouchy guy with “90 friends on Facebook…12 of them are pending” and a dream to star on a sitcom as beloved as “Two and a Half Men.”

What follows is a dim-witted road trip fastened together by scenes of Galifianakis acting as quirky as he can without the slightest bit of common sense. This might work in a movie like “Dumb and Dumber,” but not in a comedy that wants to be both stupid and sincere all in the same breath.

Downey Jr. and Galifianakis have some chemistry that keeps “Due Date” from ending up a lost cause, but without a script that really drives the story forward all that’ s left are gags featuring masturbating mammals and a joke where Galifianakis’ character mistakes a sign that says “Mexico” with “Texaco.” Could the screenwriter really not get any clever than that?