In 1969, the CTA purchased 30 New Look buses from Flxible. These buses were only 96-inches wide instead of the normal 102-inches wide. The narrower width was required for the since-eliminated #16 Lake Street route.

The 3700-series remained in service until 1991, when they were replaced with new 96-inches wide buses from Transportation Manufacturing Corporation.

The 3700-series was the last bus order Flxible would receive from the CTA until 1991.