Parking a vehicle in **double row without a driver** is considered a serious obstacle to traffic. This is because:

- **Parking in double row** means that the vehicle is parked next to another that is already parked next to the curb, thus occupying an additional lane of the road. This can block the passage of other vehicles and cause congestion.

- When the **driver is not present**, the vehicle cannot be moved quickly if necessary, which exacerbates the problem by preventing other vehicles from circulating freely.

- According to the regulations, parking in double row without a driver is classified as a **dangerous parking**, as it can obstruct the normal flow of traffic and create risk situations for other drivers and pedestrians.

For these reasons, parking in double row without a driver is a practice that seriously hinders traffic and should be avoided to maintain fluidity and safety on the roads.