[Luther]

Meil praegu kasutatavad suunatuled on ameeriklaste leiutis, kahjuks ei tea, mis aastast.

Alljärgneval leheküljel selgub, et suunatule taoline leiutis autole pärineb aastast 1916, kui C.H. Thomas kirjeldab leiutist ehk siis pirniga varustatud kinnast, mis oleks suunda näidates pimedas nähtav. Suunatuld (flashing turn signal) kui sellist esitleti esimest korda aastal 1920. Ja 1938 aastal pakkus Buick esimesena autot suunatulega.

Ingl. keelne lõik
Another noteworthy lighting feature that started as an accessory and ended up as a necessity was the flashing turn signal, introduced by the Protex Safety Signal Co. in 1920. But the idea was proposed (sort of) in 1916 when C. H. Thomas of Norristown, PA, wrote to Popular Mechanics describing an invention -- a battery and electric bulb attached to a glove so drivers could see hand signals at night.
Flashing turn signals were first offered as an option by Buick in 1938, but only as rear flashing lights. In 1940 the flashing signal was extended to front lights, and the signal switch was given a self-canceling feature.

http://www.motorera.com/history/hist11.htm