Overview
Pete Tomlin is an expert in transit signalling systems, who was employed by both the Toronto Transit Commission, the New York City Transit Authority, Hong Kong and the London Underground.
Signalling systems
Tomlin was responsible for installing the signal system on London's Jubilee line, in 1997, and the West Rail and Ma On Shan subway lines in Hong Kong, before coming to Toronto to upgrade the signal system on the Yonge-University Line.
The New York's MTA Andy Byford hired Tomlin in January 2019, who had worked under him in Toronto. Byford described his hiring of Tomlin as a "coup", because multiple other systems had wanted to hire him.
According to the New York Daily News it was his expertise in upgrading the signal infrastructure subways use that put him in demand. Many major cities share the problem of their most used lines approaching or occasionally exceeding their maximum passenger carrying capacity. Improving the signals system allows trains to run closer together and more frequently, increasing a subway line's passenger capacity. It can postpone the need for new parallel lines to be installed.
From Wikipedia (CC BY-SA 4.0).