Definition
A taxiway centerline marking modification used at certain airports in which the standard solid yellow centerline is flanked on each side by a parallel line of yellow dashes for approximately 150 feet prior to a runway holding position marking. The dashed flanking lines alert the pilot that a runway hold short marking is approaching and that increased vigilance is required.
Plain English
It is the normal yellow taxiway centerline with extra dashed yellow lines on either side, painted just before you reach a runway hold line. Those extra dashes are a visual warning that a runway is coming up soon.
Context Anchor
Seen while taxiing toward a runway, especially just before the painted hold-short lines at a runway entrance or crossing.
Derivation
“Enhanced” comes from a word meaning “to raise or make greater.” Here it means the normal taxiway centerline has been made more noticeable by adding extra dashed markings beside it.
Why Pilots Care
They provide a clear visual alert to stop and hold short unless cleared onto the runway, reducing the chance of runway incursions.
Intuition Check
Do not read “enhanced” as just “newer” or “better-looking.” In this use, it means extra dashed yellow markings added beside the normal taxiway centerline to alert you that a runway holding point is coming up.
Example Sentence 1
As we taxied toward Runway 27, the enhanced taxiway centerline markings appeared, reminding us the hold short line was just ahead.
Example Sentence 2
During night operations the enhanced markings stood out under the taxi lights and confirmed the hold-short point.