In late 1955 in Connecticut, the number of fatalities per 100,000 population in motor vehicle accidents reached a record high for the 1950s. On December 23, 1955, Governor Abraham Ribicoff took unprecedented action to reduce traffic fatalities. Ribicoff announced that persons convicted of speeding would have their licenses suspended for thirty days at the first offense, for sixty days at the second offense, and for an indefinite period (subject to a hearing after ninety days) at the third offense. Data on traffic fatalities before and after the Connecticut crackdown on speeding can be regarded as a time-series quasi-experiment with some significance for the social sciences. When supplemented with traffic fatality data for the states of Massachusetts, Rhode Island, New York, and New Jersey, the collection of observations can be viewed as a multiple-group time-series experiment.