Most important road signs are uniquely shaped or contain pictures. An inability to read--English or ANY language, for that matter--shouldn't be much of an obstacle for safe driving.
Your post is BS. Your picture shows several examples of signs that are in English and need to be understood for safe driving. If they are LEGAL immgrants, the first thing they need to do is learn English to assimilate.
Frankly, anyone from Iran is suspicious. islam is the religion of liars and murderers.