Critics of lock alert horn honking ask, "How was this allowed to happen? Isn't non-emergency horn honking illegal?" They cite noise ordinances that prohibit non-emergency horn honking, and find automakers' disregard for such laws perplexing. But just as puzzling is the disregard for common safety laws.
In the United States, anyone who drives must pass a written test and a road test. The written test is based on laws that are clearly defined in each state's driver manual. Noise ordinances focus on citizens' rights, health, and quality of life. Driving regulations focus on safety. Curious to know which states prohibit non-emergency horn honking, we read the official driver manuals for all fifty states and the District of Columbia and learned the following:
41% of driver manuals explicitly limit horn use to warning of danger
43% of driver manuals list acceptable and unacceptable forms of horn use
15% of driver manuals do not mention horn use in the context of acceptable and unacceptable usage
In 41% of manuals, the horn is designated as a safety device. In 84% of manuals, non-emergency horn use is cited as a potential cause of serious accidents due to startling or confusing drivers, pedestrians, cyclists, and animals. Many of the manuals that don't explicitly forbid non-emergency horn use still place non-emergency horn use in the context of aggression and road rage.
More than 80% of states' driving laws define the horn as a warning device whose misuse is inappropriate and capable of causing accidents. It is difficult to understand why engineers would use a warning device to indicate whether a car is locked and armed, a non-emergency situation if ever there was one. It is unfathomable that automakers would do so when quieter security indicators have always been available, and when they spent years and billions of dollars trying to make cars quieter.