Since we are on the topic of crossing volumes, here are a couple of graphs that speak wonders IMO.
PMB Volumes from 2013-2016, including straight lines of predicted volumes from 2013, 2017 (breakeven on tolling) and 2023.
2016 saw a big boost mid-year due to the Patullo construction. Looking at fall 2016, it appears that some of that volume has "stuck" as people realize the PMB is a better option. What is more concerning to me is the breakeven line. IMO we are at least 20 years away from hitting that volume at current rates. Big impacts will be new Patullo (also tolled), and potentially Skytrain to Langley (giving more people another cheaper option).
For reference, current volumes on the GMT are around ~80k/day and AFB are around ~110-120k/day.
If we picture some future where we have a new GMT/Bridge, a new Patullo, and a tolled AFB, where will the traffic come from to justify or pay for these pieces of infrastructure?
You can argue that they shouldn't be funded by tolls, but that is the way they are being sold to the taxpayer. Every dollar that is sunk into these projects is a dollar that can't be spent on a hospital, a transit line, a new school, or even a tax cut.