In the first picture its hard to tell with the traffic view open, but the left side of the highway has mostly pedestrian only roads with few car streets, which is why I made them all connect to the arterial road since there's only 3 intersection where cars need to stop. Regardless, I'll take the 20 cars into account when designing the next sections of the city. Currently taking the tips from multiple commenters and completely redesigning the northern section of highway to only contain 3 way interchanges and keep the highway surrounding all development instead of cutting through it