Providing traffic flow control services includes receiving requests at an arbiter of a traffic control subsystem. The traffic control subsystem is in a first state, and the requests are received from vehicle transmitters in proximity of the traffic control subsystem. Traffic flow control services also include applying a pre-defined condition to the requests and implementing a traffic flow control activity responsive to application of the pre-defined condition. The traffic flow control activity includes maintaining the first state or changing the first state of the traffic control subsystem to a second state.