This short film was narrated by the same guy that did "Fractured Fairy Tales" on Rocky and Bullwinkle. That's about as far as the whole "kids' short" thing goes.
I saw this film a couple of times as a primary school student in Cortland, NY, around 1975-1978, and here it is now (2006) and it still gives me the creeps. If its goal was to teach bike safety, all it really succeeded in doing was to scare the bloody heck out of me and make me never want to go near a bicycle (or any lower primates) ever again. The blithe, almost gleeful, manner in which these lawbreaking bike-riders meet their bloody fates is slightly beyond macabre and and just short of satanic. For two of the ill-fated ape-boys, just before they are bumped off, they are shown with a look of horror on their faces with their eyes bulging out in panic -- not unlike you might see in a Ren and Stimpy cartoon -- except that here it is unexpected because of the low production values (special effects? in a 1963 bike safety flick?) and because it is unexpected and not for comic effect, and it is just a few frames - the image is almost subliminal. Very haunting. The end result, if you're a single-digit age viewer of a bygone era (pre Grand-Theft-Auto, etc...) such a thing might just scare the bejeezus out of you.
In historical retrospect, it joins such classics as the 60s and 70s anti-drug scare films common to grade school health classes, and such foot-tapping Drivers Ed classics like Crimson Asphalt.