Traffic Regulation Signs

Regulatory Signs: Prohibitions, Restrictions and Mandatory Instructions

Regulatory traffic signs tell road users which rules they must follow: how fast to drive, where they may not enter, who has priority and which route they must use. The signs in this category are the TT-coded signs of the Turkish KGM system and are mostly recognised by their circular shape.

Regulatory Sign Types and Meanings

• Speed limit signs (TT-29): From 10 km/h to 140 km/h, with white or yellow backgrounds. The number inside the red ring shows the speed that must not be exceeded.
• Priority signs: The octagonal stop sign (TT-2) and give way to oncoming traffic (TT-3).
• Entry restrictions: No entry, no trucks, no bicycles, no horse-drawn carts, no handcarts, no vehicles wider than 2.30 metres and no vehicles exceeding 6 tonnes per axle.
• Overtaking restrictions and end signs: No overtaking for trucks, end of no overtaking, end of speed limit and end of all restrictions.
• Mandatory signs: Blue mandatory cycle path, footpath, bridleway and minimum speed signs, plus pass either side and roundabout signs.
• Other: Customs (no passing without stopping) and gendarmerie signs.

Sizes, Material and Sheeting

Round regulatory signs are made in diameters from 30 cm to 90 cm, and the stop sign in octagonal form. All signs are produced on 1.5 mm or 2 mm galvanized steel with standard or high performance reflective sheeting. Yellow-background speed limit signs are preferred for temporary arrangements and road works. A 30–40 cm sign usually suits estate and car park entrances, while urban and rural roads need larger diameters matched to road speed. Sign type and position are set according to the Turkish Highway Traffic Regulation.

Frequently Asked Questions

Why do regulatory signs use different colours? Signs with a red border indicate a prohibition or restriction, while round signs with a blue background indicate a mandatory instruction, so drivers immediately understand the type of rule.

Which speed limit sign suits a private estate road? Estate and campus roads typically use 20 or 30 km/h, and car parks low values such as 10 km/h. Decide based on pedestrian activity and road layout.

When is a yellow speed limit sign used? The yellow background shows the sign belongs to a temporary arrangement; it replaces the permanent speed limit during road works.