Yes, The minimum speed law. 22400a CVC
And if you are hauling something on a 2-lane road and you have more than 5 cars behind you, you are required to pull over and allow them to pass, IF you are driving UNDER the speed limit.
21654 a CVC Requires slow moving vehicles to drive as far to the right as possible, not keep up with the flow of traffic.
That's the two I was looking for. Thanks.