When you see this road sign, what is the situation in which you must keep a minimum distance of 70 metres from the vehicle in front?

The road sign indicates that when you are driving a lorry or a tractor unit with a permissible total weight over 3.5 tonnes and you are behind another vehicle of the same category, you must maintain a minimum distance of 70 metres.

This requirement is established to ensure safety by providing adequate stopping distance, particularly in situations where large vehicles may take longer to stop due to their weight.

In your case, the correct options involve scenarios where you are driving:

1. A lorry behind another lorry, both over 3.5 tonnes.
2. A tractor unit behind a lorry, also over 3.5 tonnes.

Both situations create a higher risk of collisions due to the size and weight of the vehicles, making the minimum distance crucial for safety.

The option regarding driving a lorry behind a car with a trailer is not included because the same minimum distance is not mandated in that scenario. Understanding these regulations helps promote safer driving conditions, especially for heavier vehicles on the road.