For environmental factors, no street lighting at night has the highest risk of leading to a severe accident. Good street lighting at night exhibits median risk, while daylight presents the lowest risk. Bad visibility, weekends and public holidays demonstrate a significantly higher risk of severe accidents. Moreover, midnight to dawn (00:00–6:59) is found to have a higher risk of fatal/serious injury accidents, compared to 9:00–16:00. However, accidents happening during evening rush hour 17:00–19:59 have a decreased risk of accident severity.