In general, 5 types of runway marking elements exist. These elements include:
The runway landing designator marking identifies a runway and consists of a number comprising one or two digits. These numbers are the whole number nearest one-tenth the magnetic azimuth of the centerline of the runway, measured clockwise from magnetic north.
All runway characters painted on a runway are 60ft high and 20 ft wide and spaced 15ft apart, except numerals 6 and 9 which are 63ft tall.
Any runway that requires only a single-digit landing designation will never be preceded by a zero.
For parallel runways, each runway landing designator number must be supplemented by a letter, in the order shown from left to right when viewed from the approach direction.
In the case of 2 parallel runways with a magnetic heading of 360, those runways will be marked as 36 Left, (36L) and 36 Right (36R).
3 parallel runways are marked as Left, Center, and Right.
In the case of 3 parallel runways with a magnetic heading of 36, they will each be marked as 36 Left (36L), 36 Center (36C), and 36 Right (36R).
When an airport has more than 3 parallel runways, such as the case with four, five, six, or seven parallel runways, one set of runways is numbered to the nearest one-tenth of the magnetic azimuth, and the other set of runways is numbered to the next nearest one-tenth of the magnetic azimuth.
Four parallel runways having a magnetic azimuth of 324 degrees are designated as “32L,” “32R,” “33L,” and “33R.”
Five parallel runways having a magnetic azimuth of 138 degrees are designated as “13L,” “13R,” “14L,” “14C,” and “14R”. Otherwise, they can be marked as “14L,” “14R,” “13L,” “13C,” and“13R.”
Six parallel runways having a magnetic azimuth of 83 degrees are designated “8L,” “8C,” “8R,” “9L,” “9C,” and “9R"
Seven parallel runways having a magnetic azimuth of 85 degrees are designated as “8L,” “8C,” “8R,” “9L,” “9C,” “9R,” and “10.”
Once an airport has more than four parallel runways, certain runway marking schemes for parallel runways may not be appropriate because their orientation can lead to pilot confusion.
This is especially true for airports with more than four parallel runways. For example, parallel runways on the same side of a terminal should be marked similarly. However, parallel runways separated by a large distance may benefit from not being marked as a parallel runway.
Therefore, other types of combinations can be used for larger airports in order to reduce pilot confusion.
Runway centerline markings identify the physical center of the runway and provide alignment guidance to pilots during takeoff and landing operations.
Runway centerline markings are colored white and consist of lines of uniformly space stripes and gaps.
Each centerline marking is 120ft long with an 80ft gap in between each stripe.
Runway stripes will be either 36, 18, or 12 inches in width depending on if the runway is a precision, non-precision, or visual runway.
To accommodate varying runway lengths, runway centerline markings may be reduced to no less than 80ft in length, with no less than 40ft in between each centerline marking.
The runway aiming point marking provides pilots a visual aiming point for landing operations.
Runway aiming point markings consist of two rectangular markings 150ft in length for a runway at least 4,200ft long. Runways smaller than 4,200ft long will receive markings 100ft in length.
The preferred beginning of the aiming point marking starts 1020ft from the runway threshold. However, this is not adequate for all runways cases.
The preferred distance of 1020ft from the runway threshold assumes that the runway has a standard visual glide slope of 3 degrees, no obstacles in the approach area, standard threshold crossing heights, sufficient runway length, no rapid terrain drop off near the approach threshold that encounters severe turbulence, and no elevation differences between the threshold and installation zone of the PAPI.
On intersecting runways that may encounter overlapping aiming point markings, a separation tolerance of plus or minus 200ft is allowed.
Touchdown zone markings identify the touchdown zone along precision runways and are used during landings operations.
Touchdown zone markings are spaced 500ft apart and consist of 5 groupings, with the aiming point marking serving as an independent sixth pair.
Touchdown zone markings maintain a 900-foot "no-marking zone" from the midpoint of the runway back toward the threshold. Any pair of markings that extends within 900ft of the runway midpoint is not marked.
This is to avoid pilot confusion with the touchdown-zone markings of the runways opposite the approach area.
Runway threshold markings start 20ft from the actual start point of the runway threshold and closely identify the actual beginning point of the runway threshold used for landings. This 20ft distance remains true for runways that may have a 10ft white threshold bar at the beginning of the runway used to mark the start of the runway from a displaced threshold, blast pad, or stop way.
The runway threshold marking consists of a pattern of stripes uniform in dimension space symmetrically about the runway centerline. These stripes are 150ft long and 5.75ft wide.
The number of stripes and their spacing is determined by the width of the runway and therefore can be used by the pilot to determine the width of the intended landing runway.
The number of stripes used on a runway is determined by a standard runway width of 60ft, 75ft, 100ft, 150ft, and 200ft.