Dan,
there will be traffic control at key intersxns for the entire bike and run portions of the race.
We have worked out hot spots on the bike and run where the police from each municipality will be present and close traffic for periods of time. However it is impossible to close off the roads to car traffic for the entire race. This is a normal and usual standard for every race done in the area as well as all 1/2 distances that I have raced.
I have ridden the bike course on sundays at "race time" and in northern westchester at that time on a sunday morning traffic is usually light.