By ELLEN BILTZ

As 178 kids in brightly painted cars fly down William Street in a couple weeks, Fredericksburg will once again be known as the largest soapbox derby in the world.

To many, the annual Rappahannock Regional Soap Box Derby, The Free Lance-Star Classic, is just a race. But to those children impounding their racing treasures today, it's all about pride.

"This is the last weekend, and after this, the kids won't see their cars again until the race," said Alvin Staples, the derby race director. "It's their last chance to make sure they're ready for the race.

The Fredericksburg race has broken world records in recent years for the number of participants, and while it didn't break its own record this year, it is still the largest race across the globe.

"We're not interested in trying to get more kids into the derby. We're just trying to promote the goodness of the derby like it is now," Staples said.

The three types of cars that can be entered in the race are stock, super-stock and masters, all with different weight requirements.

Stock cars have a maximum weight of 200 pounds, including the driver, and can be driven by 9- to 13-year-olds, while super-stocks can weigh no more than 230 pounds. Masters, which are driven by 10- to 17-year-olds, can weigh up to 255 pounds.

While every car has its own appearance after the body is painted or lettering is added, Staples said each car has to be built exactly the same.

The drivers also switch wheels with their opponent for part of the race to ensure that there is no advantage.

Staples said that this time of year, the derby is his life, as it is for many of the young racers. He's been working with families to make sure they're ready for the race.

Last weekend concluded the series of three derby clinics.

"The clinics are just something we do as a public service to our racers. We can help them build the car if they need it and we weigh the cars and we supply helmets to all the racers," Staples said.