Due Date (2010)

High-strung father-to-be Peter Highman is forced to hitch a ride with aspiring actor Ethan Tremblay on a road trip in order to make it to his child's birth on time.
 
Director:  Todd Phillips
Writers:  Alan R. Cohen (screenplay), Alan Freedland 
Stars:   Robert Downey Jr., Zach Galifianakis, Michelle Monaghan