Vehicles used for advertising parked in convenience layby.

From February this year there have been vehicles constantly parked, advertising businesses. One for 3 months. The layby is a convenient pull in place. for customers who use the shops, if there is no space customers drive past as there is no other option to return. I have lived here for 16 years and work from home, I know all the shopkeepers here and they all voice the same view. One Stop convenience store, Eric Lloyd Estate agents, Stockmans Funeral Services, Rowcroft Charity, and Roger Richards Solicitors, and myself Devon Leather Care. I realise that the vehicles are Taxed and Insured and have a right to be on the road, but this is NOT what thes vehicles are used for, they are a blatant advertising board. I would suggest that a time limit is placed on this layby, say 2 hours, which gives every customer a good time to shop.