Located near every koban in Japan is a sign which tallies the number of deaths and injuries caused by traffic accidents in this koban's jurisdiction in the past 24 hours. While there is no official name for this, I call it a death board.
Typically, the number of deaths is very low -- almost always single digits. This is due to the low volume of traffic in residential areas, and the generally low speed maintained at all hours due to narrow side roads and congested main roads. In the region of Suginami where I was staying with a host family, the number was usually 0 or 1 deaths and about 300 injuries. The highest number of deaths in a day I saw was 3. During common vacation times, the numbers drop significantly.
One possible reason for the high incidence of traffic-related injuries is the high number of bicycles and the lack of dedicated bike lanes. On narrow streets, bicycles must share the roads with pedestrians and cars. Except on large avenues, there are no sidewalks. Every day there are untold millions of close calls between people in transit, and of course there are the many injuries. The death board does not elaborate anything beyond the numbers, so there is no way to tell how serious the accidents were.
In very populous and well-traveled areas such as Shinjuku, the death board is a digital sign with seven-segment displays mounted high for all to see. The board does not, as far as I can tell, update in real time.
A photo of a death board: http://japan.weill.org/photos/suginami-ku/15.html