I would suggest that anyone wishing to power 30 amp RV service at their residence to weigh the additional costs and benefits of installing a 50 amp/30 amp/20 amp common power pedestal instead of a single 30 amp 120v receptacle. In my area, the combined power load centers are sold at the Big Box lumber stores so are readily available.
Cost increase of the combined load center over a single 30 amp service revolves around the larger wire used, the pedestal box, and, possibly, larger conduit (although that increase is small). The benefit is that no upgrading is needed in the future should 50 amp service be a future need, there is little voltage drop with the larger wire, and additional 120v is available at the same location.