Section 17A. Unless otherwise prohibited by federal law, the maximum speed for motor vehicles traveling on interstate highway route 90, the Massachusetts Turnpike, between the New York state border and the Westfield interchange, and from the Ludlow interchange to the Auburn interchange, interstate highway route 91 from the Vermont border to Northampton, Exit 21, and interstate 95 from the Newbury interchange 56 to the Danvers interchange 50, shall be sixty-five miles per hour.