In order to hopefully avoid having one race with a LONG delay requiring a lap count cut for every remaining race:

Existing Rule:

7.1.I. When more than 50% of the race is complete and the red flag is displayed, MRA officials may consider the race complete. If determined complete, riders will be scored according to 7.1.J.

Rewritten as:
7.1.I. Excepting the 30-minute endurance races and RoR, no race shall be allowed to consume more than 30 minutes of the race day, with the 30-minute clock starting at the time the race starts (according to timing/scoring) and ending when the checkered flag is displayed. Any race delayed by red flag or otherwise may be restarted at any time prior to the 30-minute time period expiring and the checkered flag will be displayed to the leader at the next passing after the 30-minute clock has expired. In the event that the 30 minute clock expires prior to a race restart, the race will either be considered complete and scored according to 7.1.J, or declared canceled, at the discretion of the MRA officials. When more than 50% of the race is complete and the red flag is displayed, MRA officials may consider the race complete even if the 30-minute limit has not been reached. If determined complete, riders will be scored according to 7.1.J.