In the following sentence, I believe the adjective "automobile" modifies the series of nouns "roads", "highways" and "river crossings" else the order of the list would be different... I can't seem to find a style guide or citation to back me up because it is such a poor sentence. I need to cite an authority for my criticism. Does anyone have an appropriate citation? Am I totally off base?
"New public automobile roads and highways and river crossings will not be permitted."