ECE R104

What does ECE R104 regulate?

ECE R104 establishes the approval requirements for retro-reflective markings on vehicles of categories M, N and O. It is therefore not a light, but reflective material that becomes visible by reflection once light from another vehicle falls on it.

The standard defines, among other things:

• The reflective value of the material so that the marking is also noticeable at a distance;
• the permitted colours, even in daylight;
• durability, with tests for heat, moisture, wear and aging.

Class C is usually used for the continuous contour line: the reflective strip that follows the outline of the vehicle. This allows not only the presence, but also the length and shape of a vehicle to be read at a glance.

What is ECE R104 tape?

"ECE R104 tape" is the practical designation. Technically correct, you are talking about retro-reflective contour marking. These are self-adhesive reflective strips with approval according to ECE R104 or UN R150, available in various colours.

Important: the term "tape" says nothing about quality. Non-certified tape offers no demonstrable certainties that the material meets the requirements for reflection value, durability and visibility. Only material with a valid approval does provide that assurance.

For which vehicles is ECE R104 relevant?

ECE R104 approves reflective material, but does not itself determine whether contour marking is mandatory. Whether a vehicle must carry marking, and where it should be, depends on the vehicle category, dimensions, date of first admission and national rules. The fitting obligation is anchored in the wider vehicle regulations, in particular the installation requirements in ECE R48.

Contour marking is particularly important for longer and heavier vehicles, such as trucks in categories N2 and N3 and trailers and semi-trailers in categories O3 and O4. In this context, length and width are treated as separate signals:

• On the side, the vehicle length in particular plays a role, in the ECE R48 context with a limit value round 6 metres;
• At the rear, the vehicle width in particular plays a role, with a limit value round 2.10 metres.

Not every truck is therefore required to carry R104 markings, and the limit values for length and width do not automatically apply simultaneously. The exact requirement varies depending on the situation. If you want to know exactly which lighting and markings are mandatory, you can find this information in our guide to the rules for truck and semi-trailer lighting and the lighting requirements for trailers.

What colours are used?

Contour marking has a colour logic associated with its location on the vehicle. On the side, white or yellow markings are usually used. At the rear, red or yellow markings are used, depending on the application and applicable regulations.

The marking follows the contour uninterrupted where technically possible. As the exact colour application can vary depending on the type of marking, vehicle side and country, we recommend always checking the current regulations and vehicle category when mounting rather than relying on a rule of thumb.

ECE R104 and UN R150: what about it?

Since the introduction of UN Regulation R150 in 2019, the requirements for retro-reflective devices and markings have been brought together under a single, broader framework. UN ECE R150 consolidates five older regulations: R3, R27, R69, R70 and R104.

Nevertheless, "ECE R104" often remains the designation used in the market for approved contour marking. R104-approved material remains common in the market, while R150 forms the current framework for new approvals. This distinction is useful as soon as you need to assess an approval or certificate.

Contour marking or vehicle lighting: what is the difference?

Contour marking is not lighting. It does not emit light itself, but reflects light from other vehicles. Lights such as marker lights, side marker lights and rear lights do produce their own light.

The two complement each other. Contour marking outlines the vehicle’s perimeter, whilst lights indicate its width, height and position. Together, they ensure that a truck or trailer remains recognisable as a complete object in the dark, even in poor visibility or rain. Take a look at our range of vehicle lighting for trucks.

Practical advantage: contour marking works without electricity. It only reflects back light from other vehicles. This is precisely why a vehicle remains visible even if the on-board lighting fails unexpectedly.

Frequently asked questions

What does ECE R104 mean?

ECE R104 is a UNECE approval regulation for the approval of retro-reflective markings on vehicles of categories M, N and O. The standard sets requirements for reflectance value, colour, shape and durability of the material. Since 2019, those requirements have been incorporated into the broader UN regulation R150.

Is ECE R104 tape mandatory?

That depends on the vehicle. Contour marking is generally mandatory for longer and heavier vehicles, such as N2 and N3 trucks and O3 and O4 semi-trailers. The exact requirement is determined by the vehicle category, dimensions and national regulations, not by R104 itself.

To which vehicles does ECE R104 apply?

R104 applies to heavy and long vehicles: trucks, semi-trailers and trailers. On the sides, it is primarily the length that matters, whilst at the rear it is mainly the width. The standard specifies the reflective material to be used; the obligation to fit such markings is laid down in broader vehicle regulations such as ECE R48.

What is the difference between ECE R104 and ECE R150?

R104 was the separate standard for retro-reflective markings. Since 2019, new approvals have been adapted through R150, which brought together R3, R27, R69, R70 and R104 into one framework. R104 material remains prevalent in the market, while R150 shapes the current regulations.

Official source: UN Regulation No. 150 via EUR-Lex