I used to drive the 401 a lot in the 80s, when my relatives in Toronto were alive.
I recall gravel shoulders from [insert destination - S] to London. When did those go?
I asked an Iowa DOT engineer why the DOT uses gravel for UNpaved shoulders on lightly traveled 4 lane roads. He told me if the project will fully reconstruct the existing road [I have no clue what "plus new" means, so I'm dropping it from the discussion], the shoulders protect the main road from deterioration and save money in the long run. That seems strange of Iowa. [Why did you say Illinois? You first said roads in Iowa, or "iowa," so I'm sticking to it. And I agree, this does sound strange. -S]
I do know Los Angeles and/or Louisiana [no telling what OP meant] allowed shoulder running in rush hour in the past. [Here's the rest of your periods: ............... -S] I don't think there would be anything wrong wth allowing it for limited times and only on the left shoulder [S note: That makes no sense, left shoulders are never full width], but Illinois [or is it Iowa? who cares], like Ontario, has been dead set against it. [Removed "except on no shoulder 55" because that makes as much sense as "plus new"]
Fixed grammar to be presentable. Don't care if intent was altered. If posters insist on disobeying basic rules of grammar and spelling, they get what they deserve. -S