This Sites Traffic Ratings:
Often, in the biking directions on this Internet Site, the author gives traffic ratings. These are based upon his personal experience at the time he rode the route. The author did not explicitly count traffic! These are highly subjective ratings, and probably are inconsistently applied from trip to trip. Please, do not expect that your experience will necessarily be the same as the author's!
Also, please note that traffic tends to increase by a level or two during rush hours (8-10, 5-8), and, to a lesser extent, before and after the lunch hour. It is lower than normal early in the morning and, in the countryside, during the lunch hour (1 - 2 pm).
The following table shows what the author intends to mean by traffic terms: