The question is, do you know what’s past that bridge and sign?
If you don’t – you should not take off in the first place! It’s not forced landing, but a voluntary takeoff!
It should go w/o saying, that before taking off from the road, you walk the entire takeoff run to check if there is obstacles, road damages, etc….
The risk of accelerating under the bridge is that there might be wind shear, etc. that pushes you to one side of the road. Why would you go for that risk, if after that you have miles of free and straight highway?
So as he stayed in the left lane (and per the road sign), I take it that he was taking Interstate 40 East to Ashville.