I wanted to speculate a little bit on what the primary focus for highway twinning in Northern Ontario will be once the HWY 400 extension to Sudbury is finished (dates are not clear but the final phases could start as soon as 2025-2026, based on the Northern Highways Program). Fortunately, Connecting the North, the draft Northern Ontario transportation plan, has some information I didn't notice before:
The province has highlighted the following potential priority locations for widening (in blue on the map):
- HWY 11 from somewhere around South River to HWY 17 in North Bay (even though this section is already twinned)
- HWY 17 from North Bay to HWY 144 east of Sudbury
- HWY 17 from HWY 144 to somewhere around Webbwood (a small amount of this is already twinned)
- HWY 144 from HWY 17 to somewhere around Larchwood
- The remaining section of HWY 11/17 that has yet to be twinned from Thunder Bay through to Nipigon, plus a segment of HWY 11 from Nipigon to somewhere around East McKirdy
From this info, I would guess that twinning HWY 17 between North Bay and Sudbury is most likely going to be the next priority for Northern Ontario after HWY 400, in addition to continuing the remaining work between Thunder Bay and Nipigon. The MTO grading permit controls already exist for bypasses in some locations along HWY 17 between North Bay and Sudbury.
EDIT: Made a mistake with dates.