When is an additional coupling device, such as a chain or cable, required?

An additional coupling device, such as a chain or cable, is required when a coupling device other than a fifth wheel is used. This is primarily to ensure safety and stability during towing operations. While fifth wheel couplers are designed to securely attach trailers and provide the necessary support, other types of couplings, like pintle hooks or ball hitches, may not provide the same level of reliability on their own. By requiring an additional coupling device when not using a fifth wheel, regulations aim to prevent disconnects that could result in accidents or loss of control. This promotes safer transportation of loads, particularly in commercial driving scenarios where heavier and more complex towing configurations are common.

The other options do not accurately reflect the regulations governing additional coupling devices. While bad weather and the proximity of vehicles may influence safety practices, they are not the primary reasons for requiring an extra coupling device.