The countries differ in that Norwegian drunk driving laws are generally much stricter than those in the United States, with a blood alcohol limit of 0.05 percent in Norway compared to 0.10 percent in most of the United States. The data came from 1,012 Norwegian drivers and 1,000 American drivers in 1983 and 1,800 American drivers in 1986. The 1983 data showed that 8 percent of Norwegians and 23 percent of Americans acknowledged driving while 'slightly intoxicated' in the past year. Seventy-eight percent of Norwegians and 17 percent of Americans abstained from all drinking at the last occasion if they subsequently drove. From 1983 to 1986 modest gains in compliance were noted among Americans. Further analysis of the Norwegian data showed high levels of knowledge about drunk driving laws. Results suggested four ways to improve legal knowledge in the United States: 1) national standardization of drunk driving laws, 2) simplification of penalties, 3) simplification of the terminology used regarding blood alcohol levels, and 4) monitoring systems to verify that the law is being implemented as written. Tables and 26 references. (Author abstract modified)