Assuming that half of those who disapprove of full-body scanners decide to drive instead of fly, there will be 1.86 billion more miles driven this Thanksgiving than would otherwise happen. Assuming that full body scanners make no impact on flight safety, the extra danger of driving those miles will result in three more driving fatalities than would have happened otherwise. If full body scanners actually reduce airline fatalities, the marginal death rate from driving would be even higher.
For the full calculations, see the spreadsheet.
