To reduce the load on a collection observer and prevent the accumulation of wrong toll collection information by automatically switching the output designation of a vehicle detection signal outputted from a departure detector according to the change of a toll collection method.

In this vehicle detection signal switching device 1 in a toll collection system for toll road, when the toll collection method is switched from automatic collection to manual collection by setting a service key 49a to ON state, the output designation of the detection signal outputted from the departure detector 33 is switched to an outlet lane control device 47 operated by a collecting person, and when the toll collection method is switched from manual collection to automatic collection by setting a service key 29a to ON state, the output designation of the detection signal outputted from the departure detector 33 is switched to an unmanned collection device 29.