No common carrier by motor vehicle not exempted in this chapter shall engage in intrastate operation on any highway within the state unless there is in force with respect to such carrier, a certificate of public convenience and necessity issued by the commission authorizing such operation. Any certificates of public convenience and necessity issued by the commission prior to March 8, 2018, are hereby ratified and adopted as valid and enforceable just as if they had been issued after March 8, 2018.
All certificates of public convenience and necessity issued under this chapter shall be exempt from ad valorem taxation.