Typically there are two types of RV pads: pull through and back-in sites. My comments are based only on US installations where we drive on the right side of the road and the electrical connection on the RV and at thte site are on the left side (drivers side).
With pull through sites you are limited to only using those on your side of the road for two-way traffic roads, but typically the sites are designed for one-way traffic only. Pull through sites are designed for pulling in forward only, though you could back in which would be silly.
Back-in sites are design with an angle which if looked at from above point in the direction of traffic flow. To pull in forward you would likely jack knife your trailer and depending on the slope of the entrance and how much attetion you are paying, you may bust out the rear window of your pickup if towing a 5th wheel.
Things were designed this way because if you pull in forward to a back-in site style, you block access to your means of transportation.
Thanks for the question. We tend to forget everyone is not familiar with what others of us take for granted.