We just returned home from a quick trip up to Beaver Creek and back to Whitehorse. The Alaska Highway between Burwash Landing and White River is under construction with long waits for pilot cars. Plan at least four hours between Beaver Creek and Burwash if you are southbound on the AK Hwy. We took five hours and the RV park owner in Beaver Creek told me it took motorcyclists four and a half hours on the same day.
Be prepared to get muddy. Take your time on the paved stretches that look okay; there are some good frost heaves and nasty dips. A few are good enough to get airborne and some of those aren't marked.
This 60 mile stretch is the worst I have ever seen it. Between White River and Beaver Creek it is quite nice now that construction is complete and the chipseal is down BUT keep your eyes open for crevasses that will toss your rig.