Effects of Maine's 1981 and Massachusetts' 1982 driving-under-the-influence legislation.

In 1981, Maine passed a drunk driving law with mandatory penalties and a new civil charge to increase the conviction rate. One year later, Massachusetts increased drunk driving penalties, particularly for repeat offenders and intoxicated drivers involved in fatal crashes. In Maine, single-vehicle nighttime fatal crashes declined 22 per cent the year before passage of the law, and 33 per cent the year after. Maine's rates returned to pre-law levels by the third post-law year. Prior to Massachusetts' new law, single-vehicle nighttime and overall fatal crashes there also declined 20% and 22%, whereas after this law fatal crash rates did not decline further compared with the pre-law year or other New England states. Pre- and post-law surveys indicate that both laws were followed by some increases in public perceptions that drunk drivers stopped by police would be arrested, convicted, and receive automatic penalties. But, few believed it was very likely that drunk drivers would be stopped. For only two of three years studied after Maine's law did more people there report decisions not to drive because they had drunk too much. In Massachusetts, reported driving after heavy drinking declined as much the year before as the three years after its law.