Nevertheless, Nate is looking forward to driving from their Los Angeles neighborhood to their family reunion in Missouri. Of course, that not only means a road trip halfway across the country to see his mother, Glorietta (ALOMA WRIGHT), but also having to deal with his competitive brother, Mack (STEVE HARVEY), who's determined to win the family of the year award again this year. Then there's lecherous Uncle Earl (CEDRIC THE ENTERTAINER) who's always had his eye on Dorothy.

Despite the best intentions, one thing after another goes wrong on the trip, from picking up the wrong type of hitchhiker in the form of Chrishelle Rene Babineau (SHANNON ELIZABETH) to disregarding the law. As they continue on their quest, Nate hopes to arrive on time and hopefully spend some quality time with his family.

Since most everyone's experienced such a trip at least once in their lifetime, it's easy to identify with and laugh about such vehicular trials and tribulations when they appear in the movies. National Lampoon made a mini-genre out of them with their "Vacation" films starring Chevy Chase. Now, we have an updated version of those familial road trip flicks in "Johnson Family Vacation."

Yet, where the Griswolds' antics and adventures were fun if dumb, the Johnsons' are a painful, 90-some minute trip filled with enough cinematic potholes, detours and absolute comedic gridlock to put even the chirpiest traveler in a bad mood.

Although the plot is credited to screenwriters Todd R. Jones & Earl Richey Jones (making their feature debut), it plays out more like an errant set of road directions given by someone who either didn't know where they were going or maliciously sabotaged the trip. I say that because while the movie gets from point A to point Z, it takes so much of a torturous and misguided path that one wonders where it's headed at any given moment.

That fact that it never seems as if it's going to end doesn't help matters in the slightest. While the intent is right - a comedy of errors where things progressively get worse as the trip unfolds - very little about it manages to work, let alone be funny.

Some of the material is recycled from previous works including a hot tub scene where there's no doubt that large and middle-aged, rather than young and shapely women will join the father, while a cook who doesn't wash his hands in the bathroom moment is lifted directly from "Seinfeld." Other bits simply flop, including several scenes with Shannon Elizabeth ("Love Actually," the first two "American Pie" films) as a wild hitchhiker.

The overall family strife angle doesn't work that well either. Not only do we automatically know that the separated parents will get back together again (although there's no explanation about why the wife is going to her husband's family reunion following a 3-month separation), but that material simply doesn't provide anything that's funny. It also doesn't work on the presumably intended heartfelt level.

Worse is the whole bit featuring our "hero" -- Cedric the Entertainer ("Intolerable Cruelty," the "Barbershop" films) - battling his brother -- Steve Harvey ("You Got Served," "Love Don't Cost a Thing") - for their reunion's family of the year award.

While that's what drives the protagonist through the various setbacks, none of that's funny either, especially when it directly takes over the last part of the film. It doesn't help that director Christopher Erskin (making his debut) lets such material and the overall effort drift all over the road, but Harvey's antics are only annoying rather than amusing.

Cedric does the exasperated bit as expected, but that doesn't carry the film very far, which also holds true for him also playing the family's lecherous, auto mechanic uncle. His object of desire is played by Vanessa Williams ("Shaft," "Dance With Me") who seems bored out of her mind, while Beyoncé Knowles' kid sister Solange (making her feature debut) plays the standard teen in skimpy attire. Only Bow Wow ("Like Mike," "All About the Benjamins") has the right level of energy, but he can't do anything with the lame script (that conveniently allows him time to do a brief rap bit).

Less than halfway through this constantly crashing cinematic vehicle, I kept wanting to jump out, but duty meant I had to wait until the bitter end. Others at our screening, however, did have the good sense to leave before this mess slowly puttered to a halt.

If you don't want to experience the equivalent of a painful family road trip crammed into an hour and a half of pure movie misery, you'd be wise to take a wide berth around this lame, forced and decidedly unfunny comedy. "Johnson Family Vacation" rates as a 1 out of 10.