Here's something curious: A “family” movie that seems specifically designed to discourage the creation of families.

That's the paradox that plagues “Are We There Yet?” — a vulgar, nerve-racking hybrid of “Problem Child” and “Planes, Trains and Automobiles” in which rapper/actor Ice Cube is run ragged by a pair of ungodly brats. If this is what lies in store for the average parent, maybe voluntary sterilization is the way to go.

That Cube — he of the seminal gangsta rap outfit N.W.A. and “Friday” movies — should attempt to reinvent himself as an urban Fred MacMurray is, in itself, something of a surprise (the cap-popping and spliff-rolling opportunities in “Are We There Yet?” are practically nil). In his most sober role to date, Cube plays Nick Persons, a Portland, Ore., sports memorabilia dealer so smitten with single-mom party planner Suzanne Kingston (Nia Long from “Soul Food”) that he agrees to chaperone her two preteen children to Vancouver, British Columbia, to meet her on a job site.

One hitch: The kids — bossy, impudent Lindsey (Aleisha Allen) and manipulative, polyphobic Kevin (Philip Bolden) — have vowed to sabotage the efforts of any man who courts their mother (Rube Goldberg devices usually do the trick; levers, bowling balls and buckets of glue). Thus begins an aggravatingly unfunny series of abortive plane trips and train rides that culminates with Nick being forced to shuttle the children across the border in his precious, doomed Lincoln Navigator. Though Nick detests kids (one of his many less-than-endearing traits), he manages to keep his sanity more or less together through the hellish crucible that follows — pee-pee mishaps and car fires and shoe-tying freakouts. Impressive, considering that any sane person would have Susan Smith'd their butts in the first half-hour.

Naturally, the hostility directed at Nick is rooted in pain — specifically, the pain of paternal abandonment. But instead of treating the topic honestly, director Brain Levant (“The Flintstones”) magically neutralizes it with an Alka-Seltzer finale that quickly goes flat. For all their mischief, Lindsey and Kevin never apologize to Nick, never fess up to their deeds and never come anywhere near our hearts. Ultimately, “Are We There Yet?” tries to be a story of a selfish bachelor transformed, but these particular kids aren't up to the task.