**Weekends** are the days when the highest number of traffic accidents with fatalities occur. This is due to several factors:

- **Increased nighttime and early morning activity**: During weekends, many people go out to enjoy recreational activities, which increases traffic during nighttime and early morning hours, times when more accidents are recorded.

- **Young people at risk**: Young people, especially those between 15 and 29 years old, are more prone to accidents during weekends. This is because they tend to go out more to party places and often drive under the influence of alcohol or drugs, or at excessive speeds.

- **Distractions and trips**: Weekends are common for taking trips, which increases the possibility of distractions at the wheel, especially on roads and highways.

In summary, the combination of increased nighttime traffic, risky behaviors among young people, and the increase in trips during weekends contributes to making these days the most dangerous in terms of traffic accidents with fatalities.