FEW recollections of childhood bring a chill to the bone quite like those summer holidays spent crammed in a tent with your family, suffering the whims of the British weather.

Once the sun deigned to show itself, the mass exodus to the beach would bring its own catalogue of delights: brushing sand out of tinned meat sandwiches, Punch & Judy, swatting wasps away from molten ice-cream, and the smell of calamine lotion smeared on sunburned shoulders.

Those same nightmarish memories flood back during R.V. Runaway Vacation, Robin Williams' misfiring comic caper about the outrageous misfortunes that befall a dysfunctional family during their summer holiday.

One of the hilarious' highpoints of Barry Sonnenfeld's film is Williams being drenched in the aromatic contents of an overflowing septic tank. He stinks, and sadly so does his picture.

The leading man's overpowering comic schtick (wild gesticulations, funny voices et al) cannot disguise the fatal flaws in Geoff Rodkey's screenplay, which limps painfully from one whimper to the next, punctuated by syrupy scenes of family bonding.

One of the two-dimensional characters speaks for us all when she whines, "I could actually throw up from how bored I am."

In a moment of uncharacteristic restraint, the film doesn't follow through with an explosion of vomit.

At the centre of all the mayhem is Bob Munro (Williams), an overworked, stressed out executive at Pure Vibe soda, who fondly remembers the good old days when he used to be close to his children Cassie (Levesque) and Carl (Hutcherson).

Now, the Munros barely spend any quality time together.

So Bob organises a family vacation to sun-kissed Hawaii... only for an important meeting to crop up in Colorado, which Bob needs to attend otherwise, as pointed out by his slave-driving boss (Arnett), he will be seeking alternative employment.

So, the father cancels Hawaii and crams his loved ones into a luminous, state-of-the-art rented motor-home for a road trip to the mountains.

En route, the Munros meet perky, banjo-strumming couple Travis and Marie Jo Gornicke (Daniels, Chenoweth) and their harmonising offspring Earl (Parrish), Moon (Chloe Sonnenfeld) and Billy (Ferris).

Suddenly, life on the road seems like the highway to hell...

R.V., or Relentlessly Vapid as it should be subtitled, falls apart well before the Munro clan's recreational vehicle heads for the scrapyard.

The film harps on about the importance of family unity but doesn't sketch the characters in any detail, nor develop their relationships, as they career blindly into each obstacle.

Just when you think it can't possibly get any worse, the entire cast kicks up its heels for an end credits sing-song, massacring Route 66 in a country-meets-pop-meets-rap-meets-yodelling style.

Some of the excruciating performances on The X Factor: Battle Of The Stars are positively melodic in comparison.