A vehicle ramp assembly as disclosed includes a ramp for supporting one or more wheels of a vehicle and providing a bridge over stepped terrain on which the wheels of the vehicle can travel. The ramp can move among a first configuration where the ramp is stowed in the ramp assembly, a second configuration where the ramp extends from the ramp assembly, and a third configuration where the ramp is supports the vehicle wheels as it travels over stepped terrain. A drive mechanism for the ramp, and a carriage coupling the drive mechanism to the ramp enable rotation of the ramp. A secondary actuation system enables linear movement of the carriage along the ramp. A control module can drive the carriage around a curvilinear loop, such that the ramp is driven in a cycle from the first configuration to the second configuration to the third configuration to the first configuration.