Risk of rear-end collisions on an uphill motorway or dual carriageway

This sign (*S-993*) **warns of the risk of rear-end collisions** on a stretch of **motorway or dual carriageway** with an **uphill gradient**.

On uphill sections, **lorries** and heavy vehicles usually travel at a **much lower speed** than passenger cars. This difference in speed increases the risk that faster vehicles **catch up from behind** with slower ones if the safety distance is not maintained or speed is not adjusted.

Therefore, the sign indicates that on that stretch:
- There are **slower lorries** due to the gradient.
- There is a **greater risk of rear-end collisions** due to the difference in speed.
- It is necessary to **increase attention** and **keep a greater safety distance**.