Often, the 5 and 99 freeways north of L.A. are about half/half truck/car traffic, but the car drivers are not slowed down to the speed of trucks, for the most part, because, for the most part, the truckers keep right.
And that works well because the intersections are few (about 1 per mile), announced, and routed with a separate off ramp, that is almost never to the left. Also, the speed differential is usually 55 for trucks, 65-75 for cars. This is much smaller then the speed differential of 12-25 for bicycles, 40-55 for cars on arterials, with traffic turning either left or right, and intersections possibly several times each block.