Rome as a capital town is always busy. There exist 4 rush hours: in the morning (before nine o’clock), at lunch (after 12 o’clock), after lunch (after three o’clock) and in the evening. This was typical for the last century and has been changing within the last two decades.
Besides the rush hours you may watch people relaxing, waiting for something (for example for the bus) or simply practicing their social contacts.
People like to talk to each other in Rome . Often they are using their hands heavily gesticulating, sometimes they stand beneath each other watching their environment.
People at work like to go home for lunch. In the 90’s of the last centuries the traffic situation was bad and the lunch at the bars not so far developed. People who could not go home for lunch rested during lunch time.
You always meet people waiting for some special event in Rome. This might be a street dealer waiting for a client buying some stuff, people waiting to get permission to enter, people simply waiting for the bus or other related situations.