Which Pennsylvania law substantially overhauled private passenger automobile rate regulation and rating factors in 1990?

Why this is the answer

Act 6 of 1990 amended the Pennsylvania Motor Vehicle Financial Responsibility Law (75 Pa.C.S. § 1701+) and the related rate provisions, introducing limited-tort/full-tort election, medical cost containment, and stricter PID oversight of personal auto rate filings. It is the cornerstone PA auto reform statute referenced throughout rate regulation and PIP discussions.