A little information about lead paint dust:
Milhouse, it is not a hazardous waste unless the concentration is high enough. It is a regulated waste though and should be disposed of properly. Any landfill that is permitted to accept construction/demolition debris can accept waste containing lead.
Houston54, having the paint fall off naturally over the course of many miles and many years results in lower exposure concentrations than when it is taken off all at once over a weekend.
Rusty Rod, mixing it with concrete would not keep it from leaching out.
Achipmunk, hopefully your neighbor doesn't have any small children. Here is a link to the EPA site deatailing the health risks of lead exposure with children.
http://www.epa.gov/lead/index.html 64fleetside, like Achipmunk above, hopefully your driveway doesn't serve as a playgorund for children.
We all know the dangers associated with our passion to restore old vehicles. We know not to dump antifreeze, paint thinners, petroleum based cleaning solvents or used oil on the ground where it could leach into the groundwater, harm our children, friends or pets. Let's not make the same mistake with the other wastes that we generate.