Only the towing vehicle of a semi-trailer unit is equipped with an anti-lock braking system (ABS). What could the effect of this be when performing an emergency braking manoeuvre on a wet carriageway?

The correct combination of answers highlights critical safety concerns when using a semi-trailer unit equipped with ABS only on the towing vehicle.

1. Extending the braking distance occurs because while the towing vehicle's brakes may function efficiently, the absence of ABS in the trailer means that its wheels could lock up under hard braking conditions, leading to a longer stopping distance.

2. The risk of a jack-knifing situation refers to the potential for the trailer to swing out of control. Since the trailer lacks ABS, it can lose traction: the lack of stability means that during an emergency stop on a wet surface, the trailer might pivot around the hitch, creating this dangerous scenario.

German traffic laws emphasize the importance of vehicle stability and braking efficiency, particularly in mixed-condition driving scenarios such as wet roads. Understanding the brake systems of both the vehicle and trailer is vital for maintaining control and safety in these situations.