Horn honkers take note, hold off on blowing that horn, it’s generally illegal.
§28-954. Horns and warning devices
B. If reasonably necessary to ensure the safe operation of a motor vehicle, the driver shall give an audible warning with the driver’s horn but shall not otherwise use the horn when on a highway.
From ADOT Share the Road Pamphlet:
more materials at azbikeped.org
There is ONE place where it is permissible for a driver to give an audible signal, i.e. beep (and not blast!) a horn, that is:
§28-723(2) 2. Except when overtaking and passing on the right is permitted, the driver of an overtaken vehicle shall give way to the right in favor of the overtaking vehicle on audible signal or blinking of head lamps at nighttime and shall not increase the speed of the overtaken vehicle until completely passed by the overtaking vehicle.
And note this law does not apply on any road where passing to the right, e.g. a road with two or more lanes in a particular direction, is permitted. In other words, it’s not permitted give an audible signal on a multi-lane arterial road; the only permitted use of horn is as allowed under 28-954.
In the scenario depicted in the graphic, above (a two-lane highway; passing on the right is not permitted), an audible signal is permitted but not recommended; as the cyclist cannot “give way” in any event; since there is no safe place to move to.
Arizona Department of Transportation
Bicycle and Pedestrian Program
Mail Drop 310B
206 S. 17th Ave., Phoenix, AZ 85007
© 2008 Arizona Department of Transportation.
Created by the Pima County Bicycle and Pedestrian Program,
Matthew Zoll, Program Manager.
Design and illustration by David Burnham, Pima County Graphic Services