1. A braking event detection system comprising: at least one processor; and memory storing computer-readable instructions, that when executed by the at least one processor, cause the system to: collect, by a sensor data collection device of the system, raw sensor data from sensors associated with a mobile device within a vehicle during a window of time using a polling frequency, wherein the sensors comprise a GPS receiver, an accelerometer, and a gyroscope, wherein the raw sensor data comprises information relating to a location, a speed, and an acceleration of the vehicle, and wherein the polling frequency is determined based on at least one of: the speed of the vehicle, a battery status of the mobile device, traffic information within a first threshold radius of the vehicle, and weather information within a second threshold radius of the vehicle; process, by a sensor data processing device of the system, the raw sensor data collected from the sensors associated with the mobile device to remove duplicate data points and generate processed sensor data; apply, by a braking event classification device of the system, a classification machine learning algorithm to the raw sensor data and processed sensor data to determine that a window should be classified as a braking event, wherein the classification machine learning algorithm is stored in a braking event classification model of the system; and generate and transmit, by a braking event notification device of the system, a notification to at least one of: a second mobile device within a first predetermined distance of the vehicle and a second vehicle within a second predetermined distance of the vehicle relating to the braking event of the vehicle.