Based on Beverly D'Onofrio's 1990 autobiography of the same name, the ambitious screenplay by Morgan Upton Ward ("A Pyromaniac's Love Story") hops around between 1961 and 1986 as it chronicles the life of a young woman whose dreams of becoming a writer are sidetracked when she becomes pregnant by a well-meaning, but hapless neighborhood boy. Teen-age Beverly (Drew Barrymore) repeatedly tries to better herself, but can't escape the low rent life with her baby and drug-addicted husband, Ray (Steve Zahn).

During a road trip that serves as a framing device for the film, Beverly must finally deal with the results of her impulsive and self-absorbed youth as she travels cross-country with her adult son Jason (Adam Garcia) to meet with the long gone husband and father.

In lesser hands, the whole affair could have become unbearably mawkish or grim, but Penny Marshall has a real gift for mixing humor with heartbreak. From Bev's attempts to throw herself down a stairway to Ray's "lyrical" wedding proposal ("Please marry me because I'm shit without you."), there are a lot of laughs to be had.

The casting is flawless. Although she struggles a bit while playing the upper end of her character's age range, Drew Barrymore does a wonderful job as Bev, successfully rounding out the unsympathetic aspects of the woman. Steve Zahn, who shows more depth with each new film, is just as good as Ray. Lorraine Bracco and James Woods are solid as Bev's parents and Brittany Murphy is letter perfect as best friend Fay (Just wait until you hear her impersonation of Loraine Bracco). A number of little actors play the children at various ages and they are all delightful.

Unfortunately, two very talented performers are given little to do. "Roseanne" veteran Sara Gilbert should be starring in films, not appearing in thankless supporting roles. And Rosie Perez is relegated to a few harrowing moments onscreen, looking impossibly severe. How severe does she look? Let me put it this way: Had she looked like this in "Fearless," Bubble would have leapt from her arms before the plane crashed.

Bursting at the seams with period music, sets and outfits, "Riding in Cars with Boys" takes a bleak story and invests it with magic, all without compromising any hard truths. What a pleasant surprise.