Considered one of the best –and toughest– bicycle races in America, the Snake Alley Criterion gets underway this weekend in Burlington. The eight-tenths of a mile course features one segment in the Mississippi River town’s downtown on which some people would be afraid to drive a car.Dennis Fitzgibbon, spokesman for Burlington’s Downtown Partners, says Snake Alley includes five half-turns and two quarter-turns, making it the world’s “crookedest” street, even worse than Lombard Street in San Francisco. He says the alley has a 58-foot rise over just 275 feet. It’s twisting turns and steep climb make it a tremendous feat for bikers to beat.The steep road was built in 1894 and was fashioned after roads built in German vineyards with angled bricks to give descending horses a better footing. Fitzgibbon says some competitors will have to complete the circuit 20 times, meaning, they’ll go -up- Snake Alley 20 times in a single race.The road race begins at 4:15 this afternoon, running from Burlington to Wapello and back — an 80-mile jaunt. The Snake Alley Criterion begins tomorrow at 8:45 a-m with heats running all afternoon. As many as 500 cyclists are expected, including two teammates of world biking champ Lance Armstrong from the U-S Postal Service team.