CALGARY — After more than four years of construction and at least $34 billion in costs, the Trans Mountain pipeline expansion project is nearly complete. Here's a look at what milestones to expect in the coming weeks as the massive pipeline gets ready to start shipping Canadian oil to the West Coast: Resolution of B.C. construction challenges: Crown corporation Trans Mountain Corp. has been dealing with construction-related challenges in the Fraser Valley between Hope and Chilliwack, where it en