cost of $1.1 million. As of July 2021, there are plans to replace the SD-400s and refurbish the remaining cars. Roster information Fares MetroLink uses a proof-of-payment system. Tickets can be purchased at ticket vending machines at the entrance to all stations and must be validated before boarding the train. Single ride tickets are good for up to two hours in the direction that a passenger initially boards. Some fares, such as monthly or weekly fares, do not need to be validated, but passengers must have the pass in their possession while riding and must show the pass to security personnel upon request. Passengers may also load fares onto a Gateway Card, a multi-use smart card that can be obtained at Metro's downtown retail store. In order to validate this fare type, passengers must tap their Gateway Card on the card reader at any validation machine before boarding. Metro is still in the process of fully implementing the Gateway Card. At full implementation, Metro plans to eliminate most paper passes and tickets, and passengers will be able to obtain a Gateway Card online or at any Metrolink Gateway vending machine at each station. As part of Metro's Secure Platform Plan, centralized fare collection areas will be built at all 38 MetroLink stations. Other enhancements will include fare vending equipment, state-of-the-art cameras and security systems, and improved customer assistance initiatives. The project is projected to cost $52 million, which will be funded from a mix of federal, local, and private sector funds. Reduced fares can be purchased by seniors ages 65+, people with disabilities, and children ages 5–12. Up to three children under 5 may ride free with a fare-paying rider. Proof of age may be requested of all people riding with reduced fares. Other types of passes, such as a Semester Pass for full-time students are also available in addition to the fares listed above. Extensions in progress MidAmerica Airport A 5.2-mile (8.4 km) expansion of the Red Line from Shiloh-Scott to MidAmerica St. Louis Airport in Mascoutah received $96 million in funding from the State of Illinois in 2019. This expansion will include a 2.6-mile double-track section, a 2.6-mile single-track section and a passenger station at the end of the alignment at MidAmerica Airport. Design work was completed in the summer of 2022 and a request for proposals was released that November. Construction on the expansion is expected to