Melachi Brown, 20, who police say was speeding when he collided with another driver in Maryland, pleaded guilty to six counts of manslaughter in a state court, records show.
Group cites need for better crew safeguards, citing its member firm study that work zones are either as dangerous, or more dangerous, than they were a year ago.
An out-of-control Acura, which sped through an opening in the concrete barriers separating a work zone from highway travel lanes on Interstate-695, caused six worker fatalities.