Can billboards be hung on telephone poles along provincial roads?Yes, but you have to invite bids. It seems to be under the jurisdiction of the Planning Bureau. You have to pay as much as you want every year, but if you can win the competition, you will make money. Big
Are billboards on telephone poles on the road allowed by the traffic law?It will be treated on a case-by-case basis. If you have the right to use that area, it is allowed by traffic laws, but otherwise, it is not allowed. The detailed plot involved can be found in Eagle Eye.