Chicago Picks Bike-Sharing Vendor.  Big changes are coming to Chicago’s streets, as AN has reported. One of the most visible, the city’s planned bike-sharing system, just took a major step forward with the selection of a vendor, Portland, Oregon-based Alta Bicycle Share and Public Bike System. The vendor will supply 3000 bikes and 300 solar powered charging stations this summer, according to the Chicago Tribune. The number will be upped to 5000 bikes and 500 stations by 2014. The Alta/Public partnership operates bike-sharing systems in London, Melbourne, Boston, Minneapolis, Toronto, Washington, D.C. and Montreal among other cities.