Walt Disney World has some of the world 's best attractions - and some of its longest lines.

One man has dedicated much time to helping you avoid them.

Dr Steven M Barrett, who visits Walt Disney World almost weekly, rarely finds himself waiting in the queues for rides.

He says. "I consider a wait of more than 15 to 20 minutes in line too long, he says. I just don 't do it. "

So why do so many people spend hours of their precious Disney World vacations waiting in line?

"They don 't have a good plan for touring the parks, says Barrett.

"They try to pack too much in without giving themselves rest and refreshment breaks, and they end up withering in the crowds, the heat, and the long lines."

Barrett, a practicing emergency room physician and former professor of emergency medicine, freely admits that he himself spent a fair amount of time in line during his early visits to Walt Disney World back in the 1980s.

Seeking a remedy, he turned his scientific skills to developing flexible touring plans that would keep Disney World visitors ahead of the crowds and help them pace their visits to make them truly magical.

Like any good scientist, Barrett tested and refined his plans for a number of years (on friends, family, and acquaintances) before declaring them ready for the general public.

While he was at it, he also customized them to suit the interests of three different sorts of visitors: adults and teens, families with younger children, and seniors.

The result is The Hassle-Free Walt Disney World Vacation (The Intrepid Traveler, $14.95, www.TheOtherOrlando.com).

He says: "What I 've tried to accomplish is to give both first-time visitors and seasoned WDW pros the nuts and bolts tips and information for a hassle-free vacation, says Barrett, who offers basic rules for touring, and advice on planning your WDW vacation, and plenty of insider tips, in addition to the plans themselves.