The bus will continue to operate on 31st Street between the Ashland Avenue Orange Line station and 33rd Street and King Drive through September to allow officials to evaluate bus service demand and collect more community feedback and ridership data from the route extension, officials said.
The route will extend to 31st Street Beach when it opens for the summer.
The pilot program began in September.
The CTA axed the 31st Street route in 1997 because of low ridership, and neighborhood activists have fought for its reinstatement ever since.
The 31st Street bus will continue to operate on weekdays from 10 a.m. until about 7 p.m. That limited schedule has been criticized by residents, who said the route's limited hours will significantly reduce the number of people who can use the bus.
The hours of service were selected to serve schools, multiple shopping centers and Guaranteed Rate Field, CTA officials said.
In 2012, the CTA extended the No. 35 bus to 31st Street west of Kedzie Avenue to Cicero Avenue in Little Village.