@Tes yeux noirs,
Whether you like it or not, British English speakers routinely use 'in' and 'into' about roads, highways, etc. It is the normal thing.
If "routinely used" and "normal thing" could trump accurate definitions, then you would have a point. But since I provided concise definitions for you, your point is not based in reality.
If I say "I walked along Main Street and then turned into Side Street", a British English speaker would understand that I changed direction and entered Side Street, because that is the normal way we speak
It appears that you are inclined to use others' misuse of perfectly defined words to support your position. But the definitions stand. Concerning the statement in the OP, it is not correct to say, "He turned into the road. If the definitions that I've provided are unconvincing, then what can I tell you?
Believe me, this is not an argument you can win.
You're not arguing with me. You're arguing with established definitions. And no, you can't win.
You said: "into" can be used when talking about an entry.
I said: Entry is defined as an act of going or coming in. I then provided you with this:
moving to a location on (the surface of something). A road perhaps
expressing movement or action with the result that someone or something becomes enclosed or surrounded by something else.
These definitions are not ambiguous.