Some heavy heave from the frost or a bit too much tension on those left side suspension cables.
If this were Chicago or Afgahnistan they would probably drive a few heavy duty stakes to keep this side of the bridge from overrunning the pavement any further, drop a few loads of asphalt on the joint and roller it, pop in a “Bumpy Pavement” sign and consider it good to go!
Something along those lines, along with a 10 kmh speed limit, seems like the only possible short-term solution. It will require keeping bureaucrats at bay, but handling this in a way that doesn’t tick off the northern eight ridings for the next 20 years will likely be a priority for the liberals.