According to v5_globalnews_ca, as part of its annual report, Metrolinx said it would write off $504 million spent on signalling work for the Union Rail Corridor section of its track, which began in 2013.
Metrolinx writes off $504M in Union Rail Corridor signalling costs
The massive impairment charge reflects a strategic pivot for Ontario's transit agency, as infrastructure built for a previous vision is deemed obsolete.