Next time you're cursing congested freeway driving conditions, consider this, from Michael Ronkin, posted on the New Urbanism mailing list: "20% (or higher) of all Wal-Mart merchandise at any given moment is ON THE FREEWAY SYSTEM. They've learned that goods on shelves sell, but take up space, and goods in warehouses just sit there. So they've devised a system whereby the interstate system is part of their warehousing network, warehouses on the go as it were."