## 3 The Proposed Solution
### Urban Car Accidents and Fatalities: Data Availability  
The present research focus on the urban lighting related to security and safety issues and data about the accidents. European data are widely available [71] and report accident data in different countries underlining a trend of reduction in the last decade (the data are available from 2006 to 2015). The accidents data are aggregated in three different main sectors defined by the typologies of roads: (1) inside the urban area, (2) motorways, (3) rural area (not motorways). The data show that the 37% of the accidents occur in the urban areas and the 55% in rural areas. The lower percentage of car accidents occur on the motorway. These data are describing a situation in which the problem is not strictly related to the speed of the cars (higher in the motorways) but that could be reasonably connected to the distribution of the territory infrastructure and services such as lighting. Figure 5b,c, respectively, present the distribution of female and male roles in the case of accidents. As clearly shown by the data presented in the two figures, males are generally the drivers involved in the accidents (71%), whilst females have an equal distribution in the three roles.  
Figure 5: _Cont._  
In the city adopted as a case study in the present research, data are analyzed to correlate the lighting values to the security of the roads. The city of Milan, Italy, has thus been considered as a case study and the regional databases have been adopted as data repository about car accidents and fatalities. Statistics prove that the car accidents occurring during the night are far more dangerous than the ones occurring during the day because of the visual and behavioral problems of users that increase the task difficulties (e.g., readiness to respond to stimuli, attention, drowsiness, use of substances that alter the state of vigilance, etc.). The most recent data provided by Lombardy Region [72] show that 11,604 car accidents occurred in Milan during the year 2011, around 18% of these during the night time. Although they are a small percentage of the whole number of accidents, those that occurred during the night caused 22% of the injuries and 42% of the deaths (Figure 6). These data support the concept that darkness can aggravate the visual and behavior conditions of the drivers exposing the night activities to a high level of danger and possible critical situations.  
There are many reasons that explain the statistics shown in Figure 6 and none of these should be neglected or underestimated. During the night, for example, there are more people driving under the effects of drugs or alcohol, people are tired, there are fewer police controls, etc. The inadequate lighting condition is, nevertheless, among the causes of car accidents. Therefore, considering all these issues, a correlation could be found between car accidents occurring during the night hours and incidence of car accidents.  
Figure 5: (**a**) Classification of car accidents in Europe depending on road typology (**b**) female distribution of the role in accidents (driver, passenger or pedestrian), (**c**) male distribution of the role in the accidents (driver, passenger or pedestrian).