shell road

plural shell roads

1. USA road with a bed or other layer made from shells.

   You know, the kind of New Orleans rain that […] tamps down the dust of the old shell roads and washes down the oyster stink in the French Quarter gutters and slicks up all the playground equipment and makes New Orleans smell—is it possible?—so fresh.

   2005, Chris Rose, 1 Dead in Attic, Simon & Schuster, published 2015, page 22