I put too much gravel on my drive. This caused cars to dig groves in it and tend to drift and to stall. The solution was to buy bags of postfix concret, the fast drying type. Lift out a bag sized width of gravel accross the drive. Put in enough bags of postfix to 3/4 fill the channel. Before wetting the concrete excavate the adjacent channel, turning the gravel onto the first channel. Now lay another line of concrete, still dry. Turn the next strip of gravel onto the previous channel. When complete rake over the drive area and water in. The gravel embeds itself into the postfix and you can leave just enough loose to give the desired effect. Its drivable on withing a couple of hours. You can do a long drive in sections, just starting from where you finished before. You can controll the depth of the base as you proceed. The final touch was to add sharp sand which fills in the some of the indentations between the gravel, ending up with a gravel drive that looks nice and yet is firm to drive and walk over. (The sharp sand will gradually merge into the drive).
Bob