DEL MAR, Calif. -- More than 40,000 people headed to the track Wednesday to attend opening day of the Del Mar Thoroughbred Club's 70th horse racing season.

Opening day festivities included the traditional "One and Only Truly Fabulous Hats Contest," with prizes awarded to fashion-minded guests who wear hats judged the most glamorous, funniest/most outrageous, have the best racing theme or the best fresh flowers.

The racing schedule on opening day included the $100,000 Oceanside Stakes, a mile-long race for 3-year-olds.

Horse racing at Del Mar will shift to five days a week this summer, down from the six-day format of previous seasons, a change that race officials blamed on the down economy.

Del Mar will drop most of its Monday races, with the exception of Sept. 7, which is Labor Day, according to the Del Mar Thoroughbred Club. Racing will now occur on Wednesdays through Sundays.

The 37 race day season closes on Sept. 9.

The first post will remain at 2 p.m. on all days except Fridays, when it will shift to 3 p.m.

Highlights of the racing season include the mile-and-a-quarter $1 million Pacific Classic, set for Sept. 6.

General admission on opening day is $10 and a Clubhouse ticket is $20.

The San Diego Sheriff's Department warned racegoers that additional personnel will be deployed around the Del Mar Fairgrounds to prevent drunk driving and keep the roadways safe.

"We have been committed to saving lives by aggressively seeking out and removing impaired drivers from the roadways of San Diego County," said Sheriff Bill Gore.

For more information on the racing season, click here.

For additional information on special events during the racing season click here.