In order to facilitate the flow of traffic under various conditions, the NYPD developed Traffic Stat, which identifies problem areas based on the frequency of arrests, accidents, injuries, and fatalities. It ensures that commanders in all 76 precincts are aware of traffic issues in their jurisdictions so they can address problems immediately. Traffic Stat is oriented toward giving the appropriate number of traffic citations to both movers and parkers at the right locations for the right offenses. Officers are trained to ticket for both types of violations, since both impede traffic and impact pedestrian and motorist safety. The violations that receive priority are double-parking, tailgating, red-light running, frequent lane changes, and aggressive driving, because these infractions cause the majority of accidents that involve injury or fatalities. Other violations receiving significant attention are the use of dark-tinted windows, drunk driving, and speeding. Because ticketing speeders on New York City highways is risky, all highway patrol cars are equipped with video cameras for the purpose of recording the circumstances of all traffic stops. Box junctions are used at busy road junctions. The surface of the junction is marked with a crisscross grid or diagonal painted line, and vehicles cannot enter the area so marked unless their exit from the junction is clear. "Don't block the box" is the mandate for avoiding spillback and gridlock. Blocking the box is a moving violation.