Če je naprava optična, je to utripajoča svetilka, ki se pri okvari katere koli smerne svetilke, razen dodatnih stranskih smernih svetilk, ugasne ali ostane vklopljena brez utripanja ali kaže opazno spremembo pogostnosti utripanja.
If it is optical, it shall be a flashing light which, in the event of the malfunction of any of the direction indicator lamps other than the repeating side direction-indicator lamps, is either extinguished, or remains alight without flashing, or shows a marked change of frequency.