California Code, Public Utilities Code - PUC § 778

The commission shall adopt rules and regulations, which shall become effective on July 1, 1977, relating to safety appliances and procedures for rail transit services operated at grade and in vehicular traffic.  The rules and regulations shall include, but not be limited to, provisions on grade crossing protection devices, headways, and maximum operating speeds with respect to the speed and volume of vehicular traffic within which the transit service is operated.

The commission shall submit the proposed rules and regulations to the Legislature not later than April 1, 1977.