Abstract: A multiplex transmission system for vehicles having a plurality of multiplex nodes connected to a transmission path in order to communicate information therebetween for controlling a vehicle. Each of the multiplex nodes a priority code which indicates a priority of the signals to be transmitted with the data when a plurality of multiplex nodes concurrently transmit data and accordingly the signals therefrom collide with each other. The priority data includes a first priority which attaches importance to high responsiveness for the engine and a second priority which attaches importance to safety. A detector is provided for detecting the traffic condition in the multiplex transmission path. A priority changer is provided for changing the priority respectively in accordance with the traffic condition, so that proper control of both response and safety can be reconciled.

Abstract: An operation apparatus for a vehicle automatic transmission mechanism includes an actuator for driving a hydraulic valve for switching a travel range of an automatic transmission mechanism, a control unit for controlling the actuator, and a transmission operation unit for outputting a range switching instruction to the control unit. In the preferred embodiment, the transmission operation unit includes a stroke contact type operation switch suitably mounted on a side surface of a steering column so that at least forward vehicle travel ranges can be switched by only a stretched finger of the hand of a vehicle driver who continues to maintain his grip on the steering wheel with the same hand. The operation switch can include either a rotary switch or slide switch mounted on the steering column.