---
title: "GM1 ADR-DSN.L.605 Mandatory instruction marking — Certification Specifications and Guidance Material for Aerodrome Design (CS-ADR-DSN) — Issue 7, Aerodromes · Avioverse"
description: "Except where operationally required, a mandatory instruction marking should not be located on a runway."
url: "https://avioverse.aero/regulations/easa/aerodromes/cs-adr-dsn/chapter-l-visual-aids-for-navigation-markings/gm1-adr-dsn-l-605"
---

# GM1 ADR-DSN.L.605 Mandatory instruction marking

Certification Specifications and Guidance Material for Aerodrome Design (CS-ADR-DSN) — Issue 7 · Regulation (EU) No 139/2014 · EAR revision 13 Mar 2026

GM Guidance material

## GM1 ADR-DSN.L.605 Mandatory instruction marking

(a) Except where operationally required, a mandatory instruction [marking](https://avioverse.aero/glossary/easa/marking) should not be located on a [runway](https://avioverse.aero/glossary/easa/runway).

(b) The mandatory instruction markings and information markings on pavements are formed as if shadowed (i.e. stretched) from the characters of an equivalent elevated [sign](https://avioverse.aero/glossary/easa/sign) by a factor of 2.5, as illustrated in Figure GM-L-3. The shadowing only affects the vertical dimension.

\[Figure or form omitted from this preview — available in the Avioverse workspace library.]

Figure GM-L-3. Illustration of pavement marking spacing calculation

(c) The following example illustrates how the pavement marking spacing is to be calculated:

(1) in the case of runway designator ‘10’, which is to have a height of 4 000 mm (Hps), the equivalent elevated sign character height is 4 000/2.5 = 1 600 mm (Hes);

(2) Table N-3(b) indicates numeral to numeral code 1 and from Table N-3(c) this code has a dimension of 96 mm, for a character height of 400 mm;

(3) the pavement marking spacing for ‘10’ is then (1 600/400) x 96 = 384 mm.

\[Issue: ADR-DSN/4]

GM · GM1 ADR-DSN.L.605 — Regulation (EU) No 139/2014 · ED Decision 2017/021/R · Aerodromes Easy Access Rules · EAR revision 13 Mar 2026

[All rules in CHAPTER L — VISUAL AIDS FOR NAVIGATION (MARKINGS)](https://avioverse.aero/regulations/easa/aerodromes/cs-adr-dsn/chapter-l-visual-aids-for-navigation-markings)

Consolidated from the EASA Easy Access Rules (revision 13 Mar 2026, extracted 13 Oct 2026) for convenience. Not the official publication — verify against the Official Journal of the European Union and the EASA publications before operational use.