Much of Task 2 is about what would happen if something changed, and the conditional is the only grammar that lets you say it without claiming it is happening. “If governments restricted car access, congestion would fall” argues a case without asserting either half — which is precisely what a proposal needs, because the whole point is that it has not been done.
The tenses are where this family breaks, and the break is systematic rather than random. A real possibility takes present plus “will”; a hypothetical takes past plus “would”. Mixing them — “If governments would restrict access, congestion will fall” — is one of the most recognisable first-language errors in the exam, and it appears in exactly the sentences where a writer is making their strongest proposal.
The punctuation is smaller and just as consistent. A fronted “if” clause takes a comma; a trailing one does not. “If X, Y” and “Y if X” are both correct, and “Y, if X” is not.
Present + “will” for a real possibility. Past + “would” for a hypothetical one.
The “would” goes in the result clause, never in the “if” clause. The most recognisable error in this family.
A fronted “if” clause takes one; a trailing one does not.
“Provided that”, “unless”, “as long as”. “Unless” already means “if not” — never pair it with a negative.
