One reason not to allow already small lots to be split for new structures and not having room to store construction material on the property: Scraping the street damages the street

Compared with the oil spill in the Gulf of Mexico, dumping dirt in the street and then damaging the street by using a heavy machine to scrape it up is a minor bit of environmental insensitivity. But, as an old fisherman used to say years ago, every one counts one.