The problem, according to a U.S. safety agency and accident-prevention advocates, is that these life-saving technologies are optional equipment that makes its way onto a tiny minority of vehicles. “We’re not talking about the future. This is not flying cars,” said Robert Molloy, director of the highway safety office at the National Transportation Safety Board, which on Monday called installation of such automation one of its “Most Wanted” safety enhancements. “This can be done.”

Frustrated by last year’s 7.2 percent jump in highway deaths to more than 35,000 — the steepest increase in 50 years — and the slow adoption of new technologies designed to address the problem, the NTSB has included several roadway safety issues on its Most Wanted list this year.