What's the use of having a car if players can't honk at other players or traffic in a game. GTA V is known for its realistic gameplay, and the realism when driving is never complete without a little bit of road rage.
In the GTA V universe, the horn feature has been expanded. Different cars have different horns and the horns sometimes vary even for the same type of car. Bicycles have bells instead of horns.
(Note: This is a guide for players who are new to the game)
How to honk the horn in GTA V: PC
Usually, the Left Shift key is by default assigned for honking the horn or for activating the siren in the emergency vehicles.
However, many players have commented in the GTA forums that they are unable to honk the horns using the Shift key. The other usual options for using the horn feature in GTA V is by tapping the F or the G keys (depending on if the interaction key for getting into and out of the car is assigned to the E or F keys respectively)
How to honk the horn: Xbox or Playstation
While using a controller, the button assigned for honking the car-horn is pretty much the same.
Pushing down on the left analog stick (for both Xbox and Playstation) will sound the horn or activate the siren.
Some cars have continuous horns, i.e., if the left analog key is held down, the car will keep blowing the horn. Other cars have short horns.
Additionally, players can now modify their car horns at Los Santos Customs in GTA V. The sirens on patrol cars and ambulances or even the Airtug move vehicles out of the way just like in previous games in the GTA series.
The level of attention that Rockstar pays to details is commendable and that comes to light when minute things such as horn sounds are heard.