The regulations governing LED lightbar on trucks explained

A lightbar (also known as an LED bar) may be used on a truck on public roads provided that the light function used has been correctly approved, the installation and wiring comply with the applicable regulations, and its use is permitted under national rules. An E-mark or ECE R10 approval alone is not sufficient. For use as an additional high beam, factors such as the function approval, the number of light units and the total reference value are decisive.

When is a lightbar on a truck legal?

Whether a lightbar can be used legally on a truck is assessed on three levels:

1. Product approval: is the lightbar approved for the purpose for which you intend to use it, for example as an additional high beam?
2. Installation: are the number of light units, the mounting, the wiring and the combined light output correct?
3. Use: is this light function permitted in the relevant country and in the relevant situation?

An approved lightbar may still not be permitted if it is mounted or connected incorrectly. Conversely, a light without the appropriate functional approval must not be used as driving lights on public roads.

Is an E-mark sufficient?

No. An E-mark indicates that type approval has been granted for the product or a specific function. Without the accompanying regulatory and functional specifications, the mark does not specify what the lightbar has been approved for.

You should therefore always check:

• which UN or ECE regulation applies to the marking;
• the light function for which the approval applies;
• which reference number corresponds to the main beam function;
• or whether all the functions used have been approved individually.

In our guide to the E-mark on vehicle lighting, you can find out how to recognise these markings.

What ECE approval does a lightbar require?

The required approval depends on the function of the lightbar. In the case of multifunctional LED bars , each function used must be assessed separately.

Function or component	Relevant regulations
Extra high beam	UN R149
Daytime position lights or position lights	UN R148
Amber warning light	UN R65
Electromagnetic compatibility	UN R10
Installation on the vehicle	UN R48

If you wish to use the lightbar as an additional high beam, this function must be approved in accordance with ECE R149 or a succeeding predecessor thereof that is still valid. UN R48 then sets out the regulations for installation and wiring on the vehicle.

Why is ECE R10 not sufficient?

ECE R10 relates to the electromagnetic compatibility of the product. The approval does not state that the beam is approved for use as a high beam, position light or any other light function.

A lightbar with only an R10 marking may therefore not be used as an additional high beam on public roads. This requires appropriate functional approval, such as ECE R149.

How many additional high beams is a truck permitted to have?

UN R48 generally stipulates two or four high-beam units. On heavy goods trucks in category N3, two additional high-beam units may be fitted. However, no more than two pairs may be illuminated simultaneously.

This additional option applies specifically to category N3 and does not automatically apply to every truck. Exactly which regulations apply to a vehicle also depends on the series of amendments under which the vehicle was type-approved.

For type-approval purposes, a physical lightbar may consist of one or more main-beam units. The number of LEDs or reflectors is not a determining factor in this respect. Check the type-approval documentation to see how many approved light units the specific lightbar comprises.

How does the reference number work?

An approved high-beam unit has a reference number that indicates its relative contribution to the total light output. The sum of all main-beam functions that can be switched on simultaneously must not exceed 100. The trucks’ original headlights are included in this calculation.

Calculation example: the two original headlights each have a Reference number of 17.5. Together, that is 35. If a lightbar with a Reference number of 50 can be switched on at the same time, the total comes to 85. This configuration remains below the 100 limit.

If a second lightbar with Reference number 50 is connected in such a way that it can also be switched on simultaneously, the total comes to 135. This configuration does not comply with regulations, even if all the lights have been approved individually.

You can read more about this in our guide to the Reference number for vehicle lighting.

Can a lightbar be used as a work light?

A lightbar without approval for high beam may be used as work lights, but not as driving lights on public roads. It is preferable to connect work lights separately, so that they cannot be switched on unintentionally along with the normal driving lights.

Whether an unapproved lightbar may remain fitted, covered or disconnected on the vehicle is partly determined by national vehicle and inspection regulations. Simply switching it off therefore does not automatically mean that the mounting will be accepted in every European country.

Do the same rules apply across Europe?

UN regulations harmonise the type approval and installation of vehicle lighting. A UN type approval is mutually recognised by countries that apply the relevant regulation under the 1958 Agreement.

However, national rules regarding use, periodic inspection and enforcement may vary. This is particularly relevant for work lights, amber warning lights and lighting that is fitted but not in use. For trucks operating internationally, the regulations of the countries in which the vehicle is driven must therefore also be taken into account.

You can find a more comprehensive overview in our guide to the regulations governing truck and semi-trailer lighting.

Checking the light bar before mounting

1. Decide whether the lightbar will be used as a high beam, position light, warning light or work light.
2. Check the approval and function designation for each function used.
3. Check how many approved high-beam units the lightbar comprises.
4. Make a note of the Reference number for the lightbar and the original headlights.
5. Calculate which high-beam functions can be activated simultaneously.
6. Check that the combined reference value does not exceed 100.
7. Check the vehicle category and the applicable installation regulations.
8. Check that the main beam emits white light.

Would you like to find out which model suits your vehicle and application? Then use our LED lightbar selection guide.

Frequently asked questions about light bar regulations

Is it permitted to fit an LED bar to a truck on public roads?

Yes, provided that the light function used is correctly approved, the installation and wiring comply with the applicable regulations, and national usage rules permit its use.

Is an E-mark on a lightbar sufficient?

No. Always check the specific function for which the approval was granted and the relevant regulations. For example, an ECE R10 approval does not constitute approval for use as a high beam.

How many additional driving lights are permitted on an N3 truck?

On a Category N3 vehicle, two additional high-beam units may be fitted. A maximum of two pairs may be lit simultaneously, and the total reference value must not exceed 100.

Can a lightbar certified solely to ECE R10 be used as a work light?

This may be possible, but not as driving lights on public roads. Furthermore, mounting and use as work lights must comply with the national regulations applicable to the vehicle and the situation.

ECE-approved LED bars for trucks

TRALERT® supplies LED bars complete with product specifications and approval information. This allows you to check which functions a particular model is approved for, which Reference number applies, and what data is required for the vehicle configuration.

Take a look, for example, at the Nemesis Series LED bars or our complete solutions for lorry lighting.