PARIS -- Thousands of holiday-makers were caught in traffic chaos in France on Saturday as they made their way to or from summer vacations, fueling the worst traffic jams of the year, road safety experts said.

Road safety officials said the traffic swelled from as early as 0230 GMT with tailbacks totalling 731km (453 miles) by 1100 GMT, surpassing traffic jams registered around the same time last year.

By 1300 GMT, the situation had improved slightly with cumulated tailbacks of 468km.

"I have never seen such traffic jams," one motorist told French television station LCI in France's Rhone-Alpes region, where tailbacks went as far back as 170km.

The southern Rhone valleys were the worst-hit as holiday-makers tried to reach the popular Provence region.

Another motorist trying to travel to Italy said he had decided to break for breakfast after more than an hour crawling at a snail's pace.

The government's Road Safety Unit had said the weekend would be exceptionally difficult as French families leave home for their annual summer holidays, which usually last a month, just as another group return from July vacations.

Saturday's outgoing traffic was classified as black, the worst rating on the government congestion scale.

Last year, the department registered 661km of accumulated traffic jams at 1030 GMT on August 4.

No region seemed to have been spared, with tailbacks extending to France's borders with Spain and Italy.

On the a13 motorway leading to the northwest Normandy, the situation was worsened by a demonstration dubbed "Operation Snail" by bird hunters protesting a court decision barring the government from extending the season for shooting ducks.

The protesters occasionally sounded their car horns as they crawled along.

Traffic authorities had urged motorists to drive on Sunday, when traffic is expected to be back to normal except for some possible problems in the Rhone Valley.