Position lights on trucks: regulations and use of DRL

Does your truck already have factory-fitted position lights? If so, first check how the additional lighting works in conjunction with them. An approved driving light does not automatically authorise every integrated light function.

Position lights on trucks: the rules in a short summary

• Function: DRL makes the vehicle visible during the day; low beam lights also illuminate the road.
• Approval: check for the function code RL for position lights.
• Number: UNECE R48 stipulates that two position lights are required.
• Mounting: the prescribed height is 250 to 1,500 mm above the road surface.
• Connection: DRL must switch on automatically in accordance with the applicable installation regulations.
• Colour: position lights must be white. An amber coloured light strip must not function as a DRL.
• Use: DRLs do not replace low beam headlights in the dark or in conditions of severely restricted visibility.

This article covers trucks and vans within vehicle category N and the installation framework of UNECE R48. Agricultural vehicles and mobile machinery are excluded from this explanation. For a specific installation, the applicable approval series and national vehicle regulations are also decisive.

What is position lights?

Position lights are white lights at the front of your vehicle that make it more visible during the day. The English term is Daytime Running Lights, abbreviated to DRL. This feature helps other road users to spot your vehicle. To illuminate the road, you should use low beam headlights or, where permitted, high beam headlights.

Position lights may be incorporated into the headlights or consist of separate lights. A driving light may also incorporate a position light function.

However, a light ring or LED light bar is not automatically a position light. Always check which function the manufacturer has had approved.

What is the difference between position lights, low beam headlights and sidelights?

The difference lies in their function and use. Position lights ensure visibility during the day. Low beams also illuminate the road. Position lights, also known as front position lights, indicate the presence and width of the vehicle.

Light function	Main objective	Practical application
Lighting function: Daytime Running Lights (DRL)	Main objective: To make the vehicle visible during the day	Practical use In daylight and when visibility is adequate
Lighting function: Dipped beam	Main objective: To illuminate the road and make the vehicle visible	Practical use: In the dark and in conditions where low beam headlights are required
Light function: City light / front position light	Main objective: To indicate presence and width	Practical use: As part of the statutory lighting requirements; does not replace low beams
Light function: Main beam / driving lights	Main objective: To illuminate the road further ahead with lightening	Practical use: Only when traffic conditions and regulations permit

A light can combine several functions. For example, the same light beam can serve as a position light and later function as a position light. This requires the appropriate approvals and a correct connection.

Are driving lights and LED bars permitted?

A driving light or LED bar with integrated DRL may be used on public roads, but not every light function is automatically permitted. Both the main beam and DRL functions must be approved specifically for that purpose. Does your truck already have two position lights? If so, you must not operate two additional position lights as DRLs alongside them.

In addition to functional approval, the mounting and connection must also comply with the relevant vehicle regulations. Simply bearing an ‘E’ mark or the word ‘DRL’ is not sufficient.

When selecting a product, distinguish between three components:

Section	What do you check?
Component: Main beam function	What do you check? The relevant approval for high beam headlights, for example UNECE R149 or a previous approval that is still valid
Component: Daytime Running Light function	What do you check? Approval as a position light, with function designation RL in accordance with R87 or R148
Component Installation	What should you check? Number, mounting position, visibility and switching in accordance with the applicable vehicle regulations

UNECE R148 covers several light signal functions. You should therefore check the approved function, not just the regulation number. The designation ‘RL’ stands for position light.

An R10 approval relates to electromagnetic compatibility. It does not replace a functional approval for position lights and does not guarantee trouble-free operation with every lamp monitoring system.

You can find further information on our page about ECE R87 and the approval of position lights.

Are additional position lights permitted to be switched on at the same time as the original DRLs?

No. The R48 installation discussed here requires two position lights. If your truck already has factory-fitted DRLs, the following options apply:

1. Retain the original DRLs. Use the additional lights only for other permitted, approved functions.
2. Assess a replacement DRL system. Have the new configuration assessed to ensure it complies with vehicle type-approval and installation regulations.
3. Use a separately approved position light function. To do so, check the relevant mounting and switching requirements.

Disabling the original DRL does not automatically mean that a replacement installation is permitted. You should therefore also take the vehicle’s electronics and wiring diagrams into account when making your assessment.

Does one LED bar count as two position lights?

You cannot tell this just by looking at the housing or light bar. Check the type-approval documentation and installation diagram. These must specify which lamp configuration has been approved and how it complies with the prescribed number and mounting requirements.

Two visible LED segments do not, therefore, in themselves prove that the installation comprises two approved position lights.

Are amber coloured position lights permitted on public roads?

No, not as position lights within the scope of the UNECE regulations discussed here. An approved DRL function must emit white light. An amber coloured light strip in a driving light may therefore not function as position lights. A separate approval for white position lights does not authorise the use of amber coloured position lights.

Other amber coloured functions, such as indicators, have their own requirements. You should therefore always assess the combination of colour, function and approval.

Practical example: you choose a driving light with a high beam, a white light bar and an amber coloured light bar. Check the intended use and approval status for all three. Then determine which functions are suitable for your mounting position and vehicle configuration.

What are the mounting requirements for position lights?

UNECE R48 sets out the requirements for the installation of position lights. The guidelines below apply to trucks and vans.

Section	Basis in accordance with R48, paragraph 6.19
Part No. Quantity	Basic principle according to R48, paragraph 6.19Two
Part Position	Basic principle according to R48, paragraph 6.19: At the front, facing forwards
Component: Height above the road surface	Basic requirement according to R48, paragraph 6.19: Minimum 250 mm; maximum 1,500 mm
Component Spacing	Basic requirement according to R48, paragraph 6.19: A minimum of 600 mm between the inner edges of the visible light-emitting surfaces
Component: Exception for narrow vehicles	Basic principle according to R48, paragraph 6.19: A minimum of 400 mm for a total vehicle width of less than 1,300 mm
Section: Horizontal visibility	Basic principle according to R48, paragraph 6.19: 20° inwards and outwards
Section: Vertical visibility	Basic requirement according to R48, paragraph 6.19: 10° upwards and downwards

When carrying out checks, use the prescribed light surfaces and measurement method. The external dimensions of the housing are not necessarily the correct starting point for this. Also check whether a bumper, grille or mounting bracket obstructs visibility.

How do mounting requirements differ from lamp requirements?

Mounting requirements relate to the mounting on the vehicle. Lamp requirements relate to the approved light function itself. For DRL, R148 specifies, amongst other things:

Features	Requirements for the daytime running light function
Feature: Light colour	Requirement for the daytime running light function: White
Property: Minimum light output on the reference axis	Requirement for the daytime running light function: 400 cd
Feature: Maximum light output in every direction	Requirement for the daytime running light function: 1,200 cd
Characteristic: Visible light surface in the direction of the reference axis	Requirement for the daytime running light function: 25 to 200 cm²

Candela, abbreviated to cd, describes the light output in a specific direction. These values are not intended as adjustment guidelines for the mechanic. Please refer to the manufacturer’s approval and instructions for this purpose.

Is it permitted for DRLs to be lit above the sun visor?

The DRL function must not be fitted above the maximum mounting height of 1,500 mm. In the case of driving lights mounted above a lorry cab, the mounting typically exceeds this limit.

Important distinction: a single driving light may be suitable for one function but unsuitable for another when fitted in the same mounting position. You should therefore assess the high beam and the integrated DRL separately.

The permitted combination of lights is also relevant for the main beam function. Please read our explanation of the Reference number for driving lights.

How should position lights be switched on and off?

In principle, DRLs must switch on automatically when the powertrain is operational. R48 provides for exceptions, for example when the parking brake is engaged, the automatic transmission is in park, or before the vehicle begins to move following activation of the powertrain. The specific conditions that apply depend on the relevant type-approval series and vehicle configuration.

A separate on/off switch without the required automatic function is not sufficient.

When low beam, high beam or front fog lights are switched on, the DRL function switches off automatically in accordance with the applicable R48 approval series. An exception applies to short flashes of the headlights. Additional switching conditions may apply when integrated with indicators.

Is it permitted for the light bar to remain on at a dimmed level?

This is possible when the light switches to a separately approved position light function and the installation is suitable for this. Simply dimming the DRL is not sufficient. Check both the function approval and the wiring diagram.

When installing a 24V system, also pay attention to the permitted voltage range, the fuse, connectors and any light monitoring. Follow the connection instructions provided by the lamp and vehicle manufacturers.

When should you use position lights whilst driving?

Use DRL in daylight and when visibility is adequate. Switch on the prescribed lighting when it is dark or when visibility is severely restricted. Do not rely solely on the AUTO setting. A light sensor may react differently to fog or rain than you would expect based on the traffic situation.

In the Netherlands, Article 32 of the 1990 Road Traffic Regulations (RVV 1990) stipulates that low beam headlights must be used at night and during the day when visibility is severely impaired. Article 34 provides for an exception when using fog lights under the permitted conditions. DRL alone is then insufficient.

Do the rear lights and trailer lights come on automatically?

Not always. Therefore, do not assume that active DRL also means that the rear is properly lit. Check both the truck and the semi-trailer. In conditions of limited visibility, switch on the prescribed lighting and check which functions are actually illuminated.

The Dutch government explains the use of position lights and rear lights.

What regulations apply to international transport?

Approval of the installation and the traffic regulations governing its use are separate matters. Countries may have different lighting requirements during the day. You should therefore check the official regulations for your route, including those relating to tunnels and restricted visibility.

Do not use a product approval as proof that every switch setting is permitted in every country.

Frequently asked questions about position lights on trucks

Are position lights compulsory on trucks?

The European requirement has applied to new types of trucks and buses since 7 August 2012. This means there is no general obligation to retrofit all older trucks with DRLs. Furthermore, the date for type approval is slightly different from the day-to-day obligation to have lighting fitted whilst on the road.

Are you allowed to retrofit position lights to an older truck?

Yes, in principle, an older truck without original DRLs can be fitted with an approved set of position lights. That set can then serve as the sole source of position lights. The lights, mounting and automatic switching must comply with the applicable vehicle regulations. Have the requirements applicable to your truck assessed in advance.

Can driving lights with DRL be used without connecting the DRL?

In principle, this is possible provided that the light function used and the installation comply with the applicable requirements. Check whether the manufacturer supports separate connections. The presence of an additional function does not constitute authorisation to use it.

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Disclaimer:

At TRALERT®, we do our best to keep the information in this article as accurate and up-to-date as possible, including the regulations surrounding vehicle lighting. However, legislation can change regularly, and although we make every effort to implement these changes in a timely manner, it is possible that certain updates or adjustments have not yet been incorporated into this article. We therefore always advise our readers to check the current legislation with their local government or regulatory bodies, especially when it comes to exceptions or specific national regulations. TRALERT® is not liable for any damages or fines resulting from outdated or incomplete information in this article.

If in doubt, always contact the competent authority to ensure that your vehicle meets all legal requirements.