1. A method comprising: receiving, at a computing device of a first vehicle, a first image of a second vehicle captured by an image-capture device coupled to the first vehicle and a second image captured by the image-capture device subsequent to capturing the first image, wherein the second vehicle has one or more flashing light signals; determining, in the first image and the second image, an image region that bounds the second vehicle such that the image region substantially encompasses the second vehicle; determining a polar grid that partitions the image region in the first image and the second image into a plurality of polar bins, wherein each polar bin of the plurality of polar bins is defined by two lines extending from a center portion of the image region to about a boundary of the image region; identifying, based on a comparison of image content of polar bins in the first image to image content of corresponding polar bins in the second image, one or more portions of image data exhibiting a change in color and a change in brightness between the first image and the second image; determining a type of the one or more flashing light signals of the second vehicle and a type of the second vehicle based on (i) a number of portions of image data exhibiting the change in color and the change in brightness, (ii) the color of the one or more portions, and (iii) the brightness of the one or more portions; and providing, by the computing device, instructions to control the first vehicle based on the type of the second vehicle and the type of the one or more flashing light signals.