A variably dimmable window system including a variably dimmable window having a light transmissivity; a controller in communication with the variably dimmable window, wherein the controller is configured to determine a target transmissivity to adjust the light transmissivity to correspond to the target transmissivity; and a navigational input in communication with the controller, wherein the target transmissivity is determined, in part, based on the navigational input. Methods for controlling the light transmissivity of a variably dimmable window mounted on a vehicle are also disclosed.