For the uninitiated, a trip into the land of NASCAR can be quite the eye-opening experience. Within this world, drivers, pit crews and fans pay homage to the God-given right to test the limits of both man and machine, and do so with a passion that borders on -- and often surpasses -- religious fervor.

Once thought of as a fringe sport appealing largely to the gearhead set, racing has emerged from the shadows to become the dominant spectator sport in America today. Leading the charge is NASCAR, a series whose popularity seemingly knows no limits. Impossibly fast cars, the hint of ever-present danger, and a host of charismatic drivers led by the incomparable Jeff Gordon have laid claim to the hearts and minds of sports fans of all stripes, and are the reasons hundreds of thousands will make the pilgrimage to Phoenix International Raceway for this weekend's Checker Auto Parts 500 NASCAR Weekend.

The extravaganza features four races in all and will be headlined by Sunday's Checker Auto Parts 500. More than $10 million has been poured into course improvements, including the widening of turn two and the creation of an infield tunnel. With a field including the aforementioned Gordon, Matt Kenseth, Kevin Harvick, Sterling Marlin, and up-and-comers Brian Vickers and Greg Biffle, the action should be more wide open than ever.

"This track has always produced some of the finest races we have in Winston Cup," says driver Robby Gordon. "It's a different atmosphere here in Arizona. The people in charge have done a lot of great things to enhance the race and make it friendlier for fans, and it's clear that, for the fans here, this is not only a race but an event."

More than 200,000 fans are expected to attend the four-day event, with 110,000 expected on Sunday alone. With a supermarket, hospital, police and fire department, and bathing facilities on-site, one gets a sense that NASCAR is, above all, a lifestyle choice and a self-contained community.

"Fans of this sport travel like no other, and when the race weekend comes, PIR turns into the sixth largest city in the state of Arizona," says Mike Prusinski, public relations manager for the raceway. "While local ticket sales have been improving, we actually sell more tickets outside the state than in. We'll have people from all 50 states here, and about 3,500 RVs on the property all week long. That's between 12 and 15 thousand people living at PIR for the week."

In addition to course improvements, PIR is unveiling "PIR After Dark," from 6 to 10 p.m. Friday, October 31. Driver appearances, live entertainment, food and interactive NASCAR and IRL displays are on tap for a Fan Fest being billed as the ultimate NASCAR bash.