The authors concluded that social and controlled behaviors are impaired at 0.030-0.049 g/dl in actual traffic whereas automatic behaviors are not impaired before 0.05 g/dl.
Holloway (1994, 1995) used Kruger's schema in a review for the period 1985 - 1993.
In the scientific literature, impairment refers to a statistically significant decrease in performance under alcohol treatment from the performance level exhibited under placebo treatment.
To reach statistical significance, performance differences in subjects under the two treatments must be reliable and substantial in magnitude.
They also concluded that the scientific evidence supported a reduction of the BAC limit for driving to 0.05 g/dl.
Finally, to facilitate the classification of examined behaviors, they urged investigators to include fuller descriptions of methods and procedures in reporting future research over a wider range of BACs.
To expand the boundaries of response categories into theoretical groupings without empirical studies validating that placement would only inflate the problem.
Subjects showed decreased detection of roadside signs during manual shifting in comparison with automatic transmission cars.
This is not to argue the potential value of the cognitive psychology model of driving behavior, but as Ranney's (1994) review of driving behavior models noted, accurate assignment of driving activities as controlled or automatic awaits further research.
Moskowitz and Robinson (1988) noted the difficulty of assigning studies to behavioral areas given that reports of experimental methods and procedures often are quite limited.
As an example, driving simulator studies vary greatly in the types of roads traversed, the degree of interacting traffic, the length of travel, and mental workload.