We always had signs for arei miklaot, used rarely – so that the retzahim would quickly go where they need to go without stopping to talk to anyone and creating more trouble. At the same time, there is no mitzva to have signs towards Yerushalaim, so that everyone going on regel would stop and and ask direction from everyone and inspire them. So, this is a good reason to have Arabic signs. Otherwise, they will be stopping by a makolet to ask for direction and getting into a fight.
