Law enforcement officials and safety groups say traffic deaths also fell because of targeted law enforcement efforts; a preventive focus on young drivers, and more partnerships among police agencies and others. David Harkey of the University of North Carolina Highway Safety Research Center, cautions that more study is needed to determine the actual impact of such efforts. “It’s much too early to start making the correlation that certain programs or certain interventions are what have improved our safety record,” he says. State troopers no longer patrol mile after mile in search of a speeder or drunken driver: their budgets have been hammered first by high gasoline prices and then by the shrinking economy. Technology allows officers to concentrate enforcement where the most problems occur.