The Transit Authority failed to follow state safety regulations for years by installing ceiling-to-floor turnstiles in subway stations - creating what critics call potential "deathtraps," the Daily News has learned. The revolving-door entrances and exits enabled the TA to close scores of token booths and prevent fare-beaters from entering stations by jumping over waist-high turnstiles. But the ceiling-to-floor turnstiles also could force riders to file out of stations one by one - a potential hazard during fires, terror attacks and other emergencies.