A curved multi-family road washes gravel, sandrock & general dirt over my concrete parking area with every hard rain.

It sounds like the road needs to be better graded to prevent erosion.

For your own area, a "cattle guard" sort of panel and a drainage ditch would work.

I have seen a plastic mesh that goes under gravel to help keep it in place for walkways. It might work if you put it under the gravel in front of your parking pad.

I'd be more concerned about the water, though. It sounds like your pad is lower than the driveway. Is this directing water towards your house?

A picture or 2 could really help here.

Photo

Back up and take a photo of the whole area. Perhaps one were it shows how everything is graded. Is the above photo showing the street or the concrete pad with the gravel and sand rock washed on it?

Photo

Regrade the area properly.

Roads are graded where the middle of the road is the highest and then it slopes down on both sides to reduce water build up. I can't see the exact grade but it looks like your only solution is to kill the weeds/etc at the end of your driveway and cover that area with gravel. You'll still get some gravel on your driveway but you'll have to live with that living on a gravel road and not paved.

Thanks all!