USA: Chicago commuter operator Metra has selected Transitair Systems for a $6·6m contract to provide new air filtration and purification systems for nearly 700 coaches which are not due to be replaced by the Alstom cars which it has recently ordered.

The equipment is designed to fit in the same space as the existing HVAC system, and will be tested on 50 cars before options for additional units are approved.

Air will be cleaned in a three-step process. The first step will use an electrical filter to attract airborne particles. The second step will use ultraviolet light to kill or inactivate bacteria, mould and viruses, and the in third step, air will pass through a charged field to remove or inactivate pollutants and viruses.

This is expected to eliminate 99% all airborne particulates, bacteria and viruses, including the virus that causes Covid-19.

Metra said this was only one of the many ways that it has responded to the coronavirus pandemic, with measures including enhanced cleaning of vehicles and stations with an extra emphasis on disinfecting high-touch areas and the use of electrostatic disinfecting foggers. It has installed two touchless hand sanitiser dispensers in every coach, and customers can use the Ventra app to buy and show tickets for inspection without close interactions with crews.