## 3 The Proposed Solution
### Open-Data Analysis  
Since the final aim of the research concerns the integration of the proposed method with data concerning car accidents during the night hours, the available open datasets concerning the Milan municipality (Italy) have been collected and analyzed. There are two main open datasets about car accidents in the city of Milan: the first is provided by the Lombardy Region [72] and it gives yearly data about car accidents in the city of Milan from 2000 to 2011. In this dataset, incidents are described by the means of 101 parameters regarding numbers of injuries and fatalities, time of the day when the  
Figure 6: (**a**) Car accidents in Milan, Italy during the year 2011, classified according to the time of the day of the event. (**b**) Injured people in car accidents in Milan during 2011, classified according to the time of the day of the accident. (**c**) number of fatalities during the car accidents classified according to the time of the day of the event. incident occurred, weather condition (i.e., rainy or sunny), types and number of vehicles involved (i.e., cars, trucks, bikes and bicycles), etc. The second open dataset [73] is provided by the municipality of Milan, it offers less detailed data about the accidents, namely only the number of incidents, injuries and fatalities, but it has monthly data from 2001 to 2017 divided by nine geographical zones numbered from 1, the city center, to 9 a peripheral zone in the north of Milan. Historical data from this dataset show that the number of accidents does not vary very much from the city center to the peripheral zone, but the number of fatalities changes significantly. In Zones 5 and 7, those with more fatalities, there are seven times the deaths registered in Zone 1, that with less fatalities as plotted in Figure 7. The number of accidents are more in Zone 8 and Zone 9 with a difference from Zone 1 of 5% and from Zone 2 of 50%. Noteworthy, considering the historical data about car accidents in Milan, it is possible to register a strong decrement in the time span from 2001 to 2017, as shown in Figure 8. Considering the mean of the nine zones, in 2017 there were less than half of the incidents that occurred in 2001 (from a minimum of 45% in Zone 6 to a maximum of 60% in Zone 4 and an average value of 53% of reduction). This means that security and safety campaign produced some results in the culture and control of accidents in the urban area. The less hazardous zone, i.e., those where fewer accidents occur, do not change, however, from 2001 to 2017. They are the Zones numbered 2, 4, 5 and 6 (Figure 8). The most dangerous zone in 2001, zone 9, turned out to be the third most dangerous in 2017, exceeded in number of accidents by Zones 8 and 3. The same trend discussed for the number of car accidents can be observed for the number of road accidents and consequent injuries between 2001 and 2017. The average decrease in the nine zones is around 56% (minimum 48% in Zone 6 and maximum 60% in Zone 9) (Figure 9) and the zones where fewer injuries are recorded are the ones numbered 2, 4, 5 and 6. This is not unexpected because the number of injuries is strictly correlated with the number of car accidents. Figure 7: Total number of car accidents, injured people and fatalities in the nine zone of Milan area in 2017. The left axis represents the number of accidents and injured people while the right axis represents the number of fatalities (namely, causalities). The analysis of the historical data about fatalities in car accidents does not lead to similar considerations reported for injuries data. Although there is a positive trend in the number of fatalities, which goes from a total of 82 casualties in 2001 to 40 in 2017, this cannot be said about the single zone where the trend in the number of deaths seems almost a random result (Figure 10). The maximum reduction is recorded in Zone 1 where an 80% of reduction of injuries is registered (due to also the restriction to vehicles in the city center introduced in 2011-2012, the so called area C).