Different speed limit in opposing directions

Heading along Anstey Lane from the A50tyre speed limit is 60mph (national). The road changes you 40mph further down but the sign is only on one side of the road and is a small repeater sign. There is no bigger speed limit signs on both sides of the road which would show a change of speed limit. Heading towards the A50 there is no national speed limit sign so the speed limit is only 40mph until you reach the A50. I'm guessing there is a new speed limit sign missing for each direction to show where the speed limit changes.