Don't go 10'6" x 36' just to save on vinyl costs. They key question is what size the other boards on the same highway are in the proximity of your location. If they are 14' x 48', then you have to be 14' x 48'. If you build 10'6" x 36' -- and the other signs are 14' x 48' -- then you will never be able to sell your ad space because your sign will look tiny by comparison. You have to go with the norm in the market.