As of 2021, the number of Valley commuters (
Abbotsford, Mission, Chilliwack) that actually commute outside of the FVRD is less than 22k/day; the Langleys, barely 3.5k.
Capacity of a six-lane road?
55k. Even including all the commuters headed east from Metro Van and the Sea to Sky, you'd need Abby to keep growing at 8% for the next ~50 years to warrant a fourth lane... and no amount of roadspace will clear the TCH up on weekends. Save those billions for something other than "one more lane" syndrome.