Are you required to reduce the speed to maintain a safe distance from the slower moving vehicle next to you?

The driver is required to maintain a safe distance not only from the vehicle ahead, but also from a vehicle travelling in an adjacent lane. When the lateral distance is insufficient, it is advisable to reduce speed, as this increases the time to react in the event of an unexpected manoeuvre by another driver, such as a sudden lane change. Such an action is in accordance with the principle of exercising particular caution.