I notice it most often with a smell. In my part of the west where dirt roads were very dusty they would periodically put down an oil that must contain some creosote, the same smell given off by the treated pilings at the ferry terminals on Puget Sound. One of my earliest pleasant memories combines either fishing or taking a ferry and smelling that smell of the pilings, so whenever I drove on those dusty roads (during my days working in the Cascade Mountain forests) I would smell the oil and be transported. Now that smell, often encountered near old recycled railroad ties used in garden landscaping, transports me to both the ferry dock and the dirt roads in the forest.