My neighbors and I have lodged numerous complaints about this issue to the three entities involved, and all have fallen on deaf ears. La Crescenta won't install a stop sign because, technically, the accidents are occurring in Glendale. Glendale won't do anything because the stop sign needs to be in La Crescenta. And Los Angeles County won't do anything because they're just Los Angeles County.
But I am confident the something will be done soon.
You see, a few years ago at the then uncontrolled intersection of Altura and Pennsylvania (which is several blocks south of Foothill Boulevard) a little girl was struck and killed by a speeding drunk. The powers that be saw to it that a full-blown set of traffic lights and crosswalks were set up at the scene. This site, I will remind you, also straddles the border between Glendale and La Crescenta. Evidently when a child is killed, the two municipalities manage to stop squabbling about who should bear the cost of installing intersection control. I'm sure this is a great comfort to the parents who had to bury their child that week.