Bay Area Rapid Transit District (BART) will replace the existing 669-car fleet with 700 metro cars costing $3.4bn, to handle 500,000 passengers per week in the San Francisco area.

The first car is expected to be released for test in 2013 and gets approval for production by 2016. The order of 700 metro cars will be fully executed by 2024, the railway gazette website reports.

Five interior designs are developed for public consultation.

The new cars will have three sets of doors, reduced dwell times and also a number of seats chosen to balance capacity, comfort and boarding efficiency.

There is no funding agreement in place to purchase new cars for the fleet, but BART hopes to come up with a financing plan by September.