5. Streets
When the layout was shown at a small local railroad convention, the most frequently asked question was, how did I do the streets? They're made from black sheet styrene, sanded until it turned grey, weathered with powdered chalk, and lined with colored pencils. Sealing tar and cracks were created with a Sharpie and a mechanical pencil.
Don't tell anyone, but I think double yellow lines are too modern for a 50s-era layout.