You actually gave the reason for the earth banks yourself. They were put there to stop people looking at aircraft and not at the road ahead! Why do you think all round Heathrow the perimeter fences are covered with metal panels at driver's eye height? Keep you eyes on the road in front.
I understand that but, judging by looking at car drivers, I would argue a lot still try and see around them as best they can. The real point is why not actually foster to goodwill and allow drivers to pull over like they used to at the end of runway 08. Everyone can win if you apply commonsense.