The Director of Public Safety is hereby empowered to enter into reciprocal agreements, when not in conflict with law, with other states or countries constituting an exchange of rights or privileges in the use of drivers’ licenses within this state by people who hold a valid driver’s license in another state or country; provided, that nothing herein contained shall in any way affect the revocation of licenses of another state or country. The reciprocal agreement can be annulled on notice issued to either party by the other party thereto within 30 days. No such agreement shall authorize a person who has been a resident of this state for the past 90 days to operate a motor vehicle in this state without a valid driver’s license issued by the Director of Public Safety of this state, unless otherwise authorized by law.