Bombardier Transportation announced on 29 August 2006 that it has finalized a major order for rapid transit cars from the Chicago Transit Authority (CTA), a contract valued at $577 million US (457 million euros). On 10 May 2006, the CTA Board selected Bombardier as preferred bidder. The contract is for a base order of 206 rapid transit vehicles and CTA also  exercised a first option for 200 additional vehicles for a total of 406 cars. The total number of cars involved could increase to 706 should CTA exercise all available options.

The new rapid transit cars will be the first in the CTA fleet to utilize alternating current (AC) propulsion, a technology that permits dynamic braking regeneration, lower energy and maintenance costs, and improved reliability.

Bombardier was the first rail car builder to supply AC propulsion technology to transit authorities in the United States and Canada. The new fleet of cars also will be equipped with a special leveling system to ensure that access to the car floor is level with the station platform during boarding.

The contract calls for delivery of 10 prototype cars 30 months after Notice to Proceed is given by the CTA. The prototypes will undergo nine months of revenue service testing before delivery of production series cars begins. 

The CTA operates the second largest public transportation system in the United States, covering the city of Chicago and 40 surrounding suburbs.  CTA trains provide about 500,000 customer trips each day via seven routes, 222 miles of track and 144 stations.

In North America, Bombardier Transportation is the leader in commuter rail, intercity, subway cars, automated rapid transit and automated guideway transit systems. It also maintains two of the largest multi-level commuter rail car fleets in Canada and the United States.