For runways built, refurbished or repainted after January 2008, the number of bars on the Threshold Markings indicates the width of the runway, as is described in Section 3 of the AIM. Older runways may still use an outdated scheme.
Runway threshold markings come in two configurations. They either consist of eight longitudinal stripes of uniform dimensions disposed symmetrically about the runway centerline, as shown in FIG 2-3-1, or the number of stripes is related to the runway width as indicated in TBL 2-3-2. A threshold marking helps identify the beginning of the runway that is available for landing. In some instances the landing threshold may be relocated or displaced.
You can see a picture here of the two configurations.
For configuration two, each stripe signifies what the width of the runway is.
- 60 feet (18 m), 4 stripes
- 75 feet (23 m), 6 stripes
- 100 feet (30 m), 8 stripes
- 150 feet (45 m), 12 stripes
- 200 feet (60 m), 16 stripes
1. Section 3 of the AIM