Vehicle restraining mechanism

A restraint for preventing horizontal movement away from a loading dock of a vehicle on a driveway proximate the loading dock, the restraint comprising:

• an elongated restraint arm having opposed first and second ends, said first end including a bracket shaped to engage a component of the vehicle, said second end of the restraint arm being connected to the driveway adjacent the loading dock with said first end positioned closer to the loading dock than said second end for movement of the first end between a lowered position proximate the driveway and a raised position wherein the bracket is disposed to engage the vehicle component;
• means for selectively biasing the restraint arm to the raised position;
• and
• means for locking the restraint arm in the raised position in response to a force acting on the restraint arm in a substantially horizontal direction away from the loading dock and for permitting movement of the restraint arm between the raised and lowered positions in response to a force acting on the restraint arm between a substantially horizontal direction toward the loading dock and a substantially vertical direction toward the driveway.