CHICAGO (CBS) – Chicago’s 11th annual Bike the Drive shut down Lake Shore Drive for most of Sunday morning, as thousands of cyclists rode along the lakefront.

Organizers of Bike the Drive say more than 20,000 people were registered this year – a dropoff of about 2,000 from last year.

Ethan Spotts, spokesman for the Active Transportation Alliance, says the foggy weather last year might have discouraged some people from riding this year.

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The not-for-profit Active Transportation Alliance is the beneficiary of money raised from the annual Bike the Drive event. Spotts says the average fee for riders in Bike the Drive is $40 to $45, an increase of a couple of dollars from last year.

This year’s ride was about half an hour longer than last year. Bike the Drive started at 5:30 a.m., and this year, riders had an extra 30 minutes on Lake Shore Drive, depending on where they were on the route, Spotts says.

The Drive was closed from Bryn Mawr Avenue on the north to 57th Street on the south.

The round trip is 30 miles, although riders could do less.

Spotts says there were no major crashes or medical issues in this year’s Bike the Drive, the 11th annual.