I think 8thnote nailed it. Many were designed back when there was only 48 foot trailers. Then again many are designed by clueless architects. Why would you set up a blind back? We had an architect on here one time asking how to set up a parking lot for trucks. At least he asked.
Here's a Google Map image of a new Flying J they built in Roberts, Wi. https://maps.google.com/?ll=44.962057,-92.560619&spn=0.00219,0.006137&t=h&z=18 We were looking at this one day in the office and coincidentally we were paid a visit by a Flying J salesman, for their discount program , so we asked him why they did it this way. He really didn't have an answer other than non-trucker types being the designers. We offered him our consultation services but he declined. I stopped in there one night last weekend for the first time, yep, it's a cluster****.
You can practically count on 2 hands the number of truck stops today that were around during 48 foot trailer days. 90% of the truck stops today were built in the last 10-15 years.
its the same with customers you might go to, I work a Target dedicated and while some stores the docks were set up great there are some where you think "wtf was this designer smoking" Some stores its so tight especially the blind ones its best to drop the loaded trailer on the side somewhere and completely get the empty trailer out of the dock and then have 2 docks to work your way in. I think planning should be done with a trucker with experience, not some idiot who thinks the lot/dock should go a certain way. There is also a Georgia Pacific I want to say not too far from LA where they have it setup where its one way traffic but they have it where its a blind all the way around the place instead of having you drive the other direction instead....when I went there last time there was enough room to do a 180 and get myself setup with a normal back.....I went the direction they told me, they never said how I had to back in.