Prince George’s County roads are the deadliest in the region for motorists, pedestrians and bicyclists alike, a problem that has persisted for years while county officials have been slow to react.

There were 553 traffic fatalities in Prince George’s from 2006 to 2010, for an average of 111 deaths a year — more than double the number of deaths in any other jurisdiction in the Washington region, according to data from the National Highway Traffic Safety Administration.