Woodfords Corner is already arguably the most congested location in
Portland, but I don't think there should be much adverse impact; this
is in practice where all the traffic goes anyway. (Though I have to
wonder if the original route was intended to avoid this point?)
Walton St, IMO, was never suited to carry a state highway - a narrow
residential street, lined on each side with cars parked curbside, such
that when two passenger cars approached in opposite directions, things
got dicey. Trucks? Yeah right!
This reroute shortens ME-9 by about 0.4 mi.
Final verdict: Good form, MDOT!