A place I worked at had a parking lot about two feet lower than the lot to the south. Instead of putting in a retaining wall they paved the slope at 45 degrees, everything was asphalt and no problem from our side.I would put at least half of that on the design of the parking lot. What looks to be a 2 foot drop and no curbstones? That's dangerous.
One day a loaded dump truck swung wide, cutting through the lot and went over the drop. It didn't tip over but some of its dirt got thrown out. It now has precast curbs, a token effort particularly in winter.