Provided herein are vehicle restraint systems for releasably securing a vehicle having a RIG bar to a loading dock. The vehicle restraint systems can include a vehicle engagement member, such as a restraint hook, that is configured to engage RIG bars having a variety of geometries, including conventional RIG bars having a square cross-sectional area and modified RIG bars having more complex geometries. The engagement member can include an engagement region having a scallop feature configured to provide clearance for the RIG bars during engagement.