Both answers above are valid and in more than 50 years of RVing I have never had anyone measure the length of it or of my rig. The only time that I encountered the lines on the pavement to judge length, it was there for the RVer's use along with a caution if you didn't fit between the lines. In an OR state park I watched an over length fifth wheel get hard up against a tree when attempting to make the turn to leave the campground after he had managed to get it in the site assigned several days previous. It took 2 wreckers to get the trailer moved sideways and he also had damage, all of which was his problem alone. I also saw a travel trailer hung up on a rock outcropping in a national park and he was pulled off of the rock with a park service tractor to clear the road for others to use, which did more damage to the RV. When in Corps of Engineers parks, you are expected to get the RV into the site to clear the road and it is common for an RV to overhang the rear of the site with no objection from the staff about the length exceeding the state site length but the do expect you to be completely clear of the road with all vehicles and I have seen them make someone part the tow vehicle in a different parking area to do that. We were once refused entry into a commercial park as we were too small for the class of customers that they catered to. That was a minimum RV size, not maximum.
That too depends on the storage facility. Most of them rent the space by the foot and you are required to get entirely inside of the space but they do not care how so long as you fit. While they do not measure your RV, they do require that it be entirely within the assigned site. Where we last kept our travel trailer there were several of the larger sites that were used to keep 2 smaller trailers in one site.
Odd that they would do that to the site. That is very narrow. Wonder what their reasoning was?
Right. The stated site size is for the RV alone, not any accessory vehicles. You may even be required to park a tow vehicle, towed car, or dolly elsewhere.
Very likely the obstacles are placed to keep people from driving off of the pavement. Having been a volunteer in numerous public park campgrounds over the years, I have seem many ruts, run over vegetation, and assorted other damage from drivers who had wheels track off of the pavement.
One factor that plays a major roll in the size of RV which can use many campsites is the driving skills of the person who is using the RV. Very often the limiting factors in who can fit into an RV site are things like the width of the roads, the obstructions that are very close to the roads, and even the angle at which a back-in site is to the road. I have seen some RV drivers put their rig into sites that I'd never attempt and I have also seen drivers who had great difficulty geting parked in the mose accessable site. We were once in a campground that had two deep dips that the road passed through which could cause a longer RV to get hung up. In one of them the park rangers brought in a ramp to place into one of the dips when a host arrived or departed so that they could get larger RVs into the amply large host site, then removed and stored it. That campground had a maximum size of 30' and the host (who we spoke with) had a 42' fifth wheel in the host site which he indicated was not difficult with the provided ramp in the dip that he had to pass through. The wash involved was dry most of the time but had water during any rain storm and prevented flooding in the campground.
