Just pay attention to the trial running section. For the REM it went smoothly. For the confed line (which features a number of the same characters as the crosstown) they decided to gloss over "minor" issues during the running, and we all know how that turned out. For the trillium line they went total opposite, and kept it running forever until there wasn't the slightest hiccup. The worst case scenarios which are unlikely are like Edmonton, with the Metro Lines signalling proving unreliable and the Valley line revealing infrastructure issues