The Des Moines B-cycle program, which offers participants a green alternative to cars for short commutes and errands, launched Wednesday. Daily, monthly and yearly memberships, at a cost of $5, $30 and $50, respectively, give members access to 18 B-cycles at four downtown B-stations, including Brenton Skating Plaza, Principal Park, Seventh Street and Grand Avenue, and 13th Street and Grand Avenue. Operated by Des Moines Bicycle Collective, B-cycle is sponsored by Wellmark Blue Cross and Blue Shield of Iowa, DriveTime Des Moines, the city of Des Moines, the Polk County Health Department, the Greater Des Moines Convention and Visitors Bureau, Polk County, Principal Financial Group Inc., Nationwide Mutual Insurance Co. and the Des Moines Regional Transit Authority. Des Moines is the fourth U.S. city to roll out a bike sharing program. Free day passes are being offered through Sept. 14. For more information, go to http://desmoines.bcycle.com.