Taxicabs of the United States area. The president of United Cab discourages his drivers from carrying firearms, instead advising them to accelerate the car and crash into a lamppost or even a police car if they are threatened with a gun. Uber is a major competitor to taxi companies, providing on-demand for-hire car service through a smartphone app in many US cities. Uber services are generally treated as black-car services from a legal standpoint and are not generally regulated under Taxi laws. This can cause friction with both local governments and taxi companies. In June 2015, the city council voted unanimously to increase taxi fares;
Acoustic hailing device Acoustic hailing device An acoustic hailing device (AHD) is a specialized loudspeaker that emits high-power sound waves for communicating at a distance. AHDs vary in design, output, and usability. Acoustic hailing devices are acoustic devices capable of outputting highly intelligible sound at very high volumes. The distance at which acoustic hailing can be effective varies based on several factors including the sound level, directionality, and frequency of the acoustic source, the sensitivity and directionality of the receiver, and the transmission channel environment. The sound level diminishes or attenuates with distance. Consequently, as a general rule, higher source levels have greater