1. A computer-implemented method for automatic toll booth interaction with self-driving vehicles (SDVs), the computer-implemented method comprising: interrogating, by a self-driving vehicle (SDV) interrogation transceiver at a toll booth, a driving mode module on an SDV, wherein the SDV is capable of being operated in autonomous mode by an on-board SDV control processor, wherein the driving mode module selectively controls the SDV to be operated in the autonomous mode or in manual mode, and wherein the SDV is controlled by a human driver of the SDV if in the manual mode; receiving, by the SDV interrogation transceiver, a driving mode descriptor of the SDV, wherein the driving mode descriptor identifies whether the SDV currently is operating in the autonomous mode or in the manual mode while traveling on a toll road; and transmitting, by one or more processors, an adjusted toll charge for the SDV to travel on the toll road based on the driving mode descriptor.