The shares of vehicles before the lockdown were estimated based on the total number of registered vehicles in each category in the city extracted from Automobile Club d'Italia ( http://www.aci.it/ ) , and the hourly flow extracted from a report by 5 T S.r.l . on vehicular mobility in the Piedmont region ( 5 T and Regione_Piemonte , 2019 ) . For the lockdown period , the share of each category in the hourly traffic flow in both working and non - working days was considered in the simulation . Since no data on the share of each of the 44 specified categories in the hourly traffic flow of Turin was available , and this type of data could not be extracted from the recorded traffic flow , an estimation for the share of these vehicles in the traffic flow was made . The data regarding the circulating vehicles was estimated based on the average number of kilometers traveled , and the data regarding the registered vehicles were considered in order to verify the consistency of the disaggregation into categories .