Caltrans estimates that for every minute a lane is actually blocked, traffic will remain slow for an additional two to five minutes. This explains why traffic may slow down and then speed up for no apparent reason long after the crash has been removed. Traffic Control is serious work. In 1996, a CHP Officer was struck by a vehicle and killed while directing traffic outside a concert. I personally know of several officers who have been hit and injured by inattentive or inebriated drivers while they were directing traffic.
Highway includes street.
Thus, technically, the words Street and Highway are interchangeable. Different types of roads have acquired many different names over the years. These names also vary from one region of the United States to another. The words Expressway and Motorway are seen more often in the eastern half of the country. An Expressway is very similar to what Californians call a Freeway.