US rail operator Metrolink has been granted $21.3m in federal stimulus money to install positive train control (PTC), a computerised safety system to prevent train-to-train collisions.

A severe collision between a Metrolink train and a freight train in September 2008 claimed 25 lives and injured over 130 people when a train driver crossed through a red light.

The collision was followed by the government making it mandatory for most railways to install a PTC system by 2015.

The system prevents collisions by automatically enforcing speed restrictions.

Metrolink’s grant includes other safety and capacity systems improvements.