You're off on your holidays with a medium-sized suitcase. Modern suitcases have little wheels at the bottom, sometimes two, sometimes four. On a smooth airport concourse the suitcase fairly flies across the floor. But in my case, long before I reach the airport, I have to drag the suitcase over rough tarmacadam road, and the tiny wheels can't cope. They get hooked in the grit forming the road surface. The rougher the road, the harder it is to pull the suitcase.
I have had a lightweight two-wheeled shopping trolley for years, so I removed the shopping bag from it and lifted the suitcase on to the trolley platform. It fits! All it needs is a bungy cord at the top and bottom to steady it, and then I can pull my suitcase over really rough ground without any problem.
At the airport, I find a quiet corner, collapse the trolley and place it inside the suitcase before checking in. The trolley weighs about 2kg, so adds little to most luggage.
That's it! The pictures should be self-explanatory! Note that you'll have to find a shopping trolley that is foldable. But these are easily available on the internet. I paid £8.99 for mine in the UK, which is about 12 bucks US. I already had the bungy cords.
The dimensions of the trolley when folded completely flat (without the shopping bag attached) are: 53cm x 28cm x 12cm (length x width x height). This particular trolley, folded, would even fit inside a smaller suitcase, but you'll have to experiment there.