fog line

plural fog lines · alternative fogline

1. The boundary of a body of air, contacting the earth's surface, that has fallen below the dew point and usually contains fog.
2. A division in altitude above which fog appears.

   Along the coast Sequoia sempervirens does not grow above the altitude to which the moist sea air generally rises — the fog-line, as it is often called.

   1895, On the Various Stages of Development of Spermatobium, with Notes on Other Parasitic Sporozoa

   2 more examples

   Along the base of the Sierra, back of Pasadena, on eastward back of San Gabriel, past Cucamongo, with its noted vineyards, above Pomona and on beyond San Bernardino, growing warmer as it recedes eastward from the sea, is a belt of foothills above the fog line, facing out toward the noonday sun, looking down across the plains and the hills of the Coast Range upon the warm, southern sea, and yet fanned daily by an ocean breeze that has no harshness.

   1884 June 28, The Overland Monthly, page 596

   Up on the ridges above the valley, way above the fog line at between 400 and 700m (1300 and 2300ft), are some great old Zinfandel vineyards, their origins dating back to the sites that were first planted by Italian immigrants back in the closing decade of the 19th century.

   2002, Oz Clarke, Oz Clarke's New Wine Atlas: Wines and Wine Regions of the World

3. A line painted on a road (usually bright white) that marks the edge of the legally drivable portion.

   The reference line is a straight line that runs the length of the accident site, such as a fog line on a straight road.

   2006, Truck Accident Litigation, volume 978, page 45

   2 more examples

   As the driver of the vehicle reached into the glove box to obtain the insurance information another westbound vehicle crossed the fog line traveling onto the north shoulder of the roadway.

   2003, Isaiah McKinnon, In the Line of Duty: A Tribute to Fallen Law Enforcement Officers from the State of Michigan

   And I believe you commented somewhere about how the fog line broke at that point and then picked up on the other side of the entrance ramp.

   2015, Robert L. Habush, Art of Advocacy Series: Cross Examination of Non-Medical Experts