Alstom deploys ATO on Paris RER Line A May 10, 2017 | Europe Company News Alstom has deployed an automatic train operation (ATO) technology on the Nanterr to Préfecture and Val-de-Fontenay to Fontenay-sous-Bois sections of the Paris RER Line A under a EUR20 million contract... This content is available to only subscribers. Username or E-mail Password Remember Me Forgot Password