Road narrowingMexico
Traffic rules
Mexico
1. Road narrowing
A road narrowing is a section where the available width of the road or carriageway becomes smaller. The narrowing may occur on both sides, on one side only, or because one or more traffic lanes end.
Drivers should reduce speed, observe approaching and adjacent traffic, maintain sufficient lateral clearance and merge when necessary. Warning signs do not always determine priority, so drivers must follow any priority signs, lane markings and local traffic rules.
What does a road-narrowing warning mean in Mexico?
Mexico’s national sign manual identifies narrowing roadways and bridges through warning signs. Read any separate regulatory control and apply the state or municipal rules for passing and merging.
Warning for a road narrowing.
English • Traffic sign SP-20 • Symmetrical narrowing. The road narrows on both sides. Available width or the number of lanes may decrease.
Español • SP-20 • Reducción simétrica. La vía se estrecha por ambos lados. Puede disminuir el ancho disponible o el número de carriles.
Sources
🔗 Commons.wikimedia.org (Amateria1121 • CC BY-SA 3.0)
🔗 Dof.gob.mx • SICT/SEDATU · Manual federal 2024, p. 155 del PDF
SVG source: Commons.wikimedia.org • Original SVG
Amateria1121 • CC BY-SA 3.0 • Original revision 2014-03-09. Wikimedia original unmodified.
Artwork reviewed against the Mexican federal Manual de señalización y dispositivos para el control del tránsito en calles y carreteras (2024): Dof.gob.mx • SP-20, PDF page 155. Intentional educational illustration update from the previous PNG; original SVG unmodified.
Warning for a road narrowing on the right.
English • Traffic sign SP-21 • Asymmetrical narrowing on the right. Available width or the number of lanes may decrease.
Español • SP-21 • Reducción asimétrica por la derecha. La vía se estrecha por el lado derecho. Puede disminuir el ancho disponible o el número de carriles.
Sources
🔗 Commons.wikimedia.org (Amateria1121 • CC BY-SA 3.0)
🔗 Dof.gob.mx • SICT/SEDATU · Manual federal 2024, p. 155 del PDF
SVG source: Commons.wikimedia.org • Original SVG
Amateria1121 • CC BY-SA 3.0 • Original revision 2014-03-09. Wikimedia original unmodified.
Artwork reviewed against the Mexican federal Manual de señalización y dispositivos para el control del tránsito en calles y carreteras (2024): Dof.gob.mx • SP-21, PDF page 155. Intentional educational illustration update from the previous PNG; original SVG unmodified.
Does a narrowing warning give you priority in Mexico?
No. A warning describes the reduced width, rather than allocating priority or setting a numerical speed limit. Follow any separate priority signs, signals and meeting rules, and slow enough to pass safely or wait before entering.
What should you do if traffic lanes merge at a narrowing in Mexico?
Read the lane-ending signs and markings, check surrounding traffic and signal any lane change as required. Apply the local merging rule and enter only when safe. Do not assume the driver in an ending lane always has priority, or confuse merging with meeting oncoming traffic.
