The effect of Ralph Nader's book Unsafe at Any Speed was that seat belts were made mandatory in cars.
Unsafe at Any Speed is a book written by Ralph Nader, which was published in 1965. It presents arguments about the resistance of automobile manufacturers to the introduction of safety measures, such as seat belts, and their general aversion to spend money on improving the safety of their products. One example of the book was the Chevrolet Corvair car from General Motors.