C28 Prohibition Sign – Differentiated Speed Limit 50/30 km/h, Ø60 cm, Class I

C28 Prohibition Sign – Differentiated Speed Limit 50/30 km/h, Ø60 cm, Class I

The C28 puts two speed limits on one sign: the upper value, with a car outline, for motor vehicles, and the lower one, with a lorry outline, for goods vehicles. This sign shows 50/30 km/h.

When class I is used

The sign has class I (RA1) retroreflective sheeting: 70 cd/(lx·m²) for white and a 7-year service life. It is the economical choice for places without many light sources, such as local, minor and private roads or streets without strong lighting. Where there is street lighting, shop windows or advertising, SR 1848-2 requires prismatic class 2 or 3 sheeting, which stands out better against a lit background.

Where it goes, under SR 1848-1:2024

It goes at the start of a section where goods vehicles may not exceed the speed in the lower part of the sign and other motor vehicles the speed in the upper part. The end of the limit is signed with the C33 (end of all restrictions).

Like all prohibition signs, it goes right after the junction before the restricted place, so drivers can go round without turning back, and it is repeated after every junction on the section. Exemptions for residents or certain vehicle categories are shown on the P34 and P18 additional panels.

Technical data

• 60 cm diameter disc (normal format, SR 1848-2): white with a red border, with the values 50 and 30 km/h and the outlines of a car (top) and a lorry (bottom);
• 1 mm galvanised steel sheet, with pressed edges, no sharp edges;
• electrostatically painted with UV-resistant paint;
• class I retroreflective sheeting (RA1), resistant to UV and weathering, with a 7-year service life;
• weight: 3 kg;
• fixings included: 2 clamps for Ø48 mm posts and 4 bolts with nuts;
• CE marked; compliant with SR EN 12899-1:2007, SR 1848-1:2024, SR 1848-2:2011 and SR 1848-3:2011.

Mounting and size

Fixings for the post are included: 2 clamps for Ø48 mm posts and 4 bolts with nuts; clamps for Ø60 mm posts are available on request. The bottom edge of the sign goes 1.50–2.50 m above the road or kerb, and the edge nearest the road 0.50–2.0 m from the road platform. The sign must be visible from at least 50 m in built-up areas and 100 m outside them.

The post is ordered separately. For a fixed installation in a concrete foundation: the galvanised Ø48 mm post, 300 cm. For temporary use, with no foundation: the Ø48 mm tripod post, 120 cm. On concrete or paving, where you cannot dig: the Ø60 mm flange post, 300 cm, bolted down; for it, ask for the Ø60 mm clamps when you order.

The 60 cm diameter is the normal format in SR 1848-2, for county and local roads, streets and private roads open to public traffic. National roads call for the large Ø80 cm format and motorways for the very large Ø100 cm one; the standard forbids using a smaller format than the road category requires.