08/06/2016
Navigating the specifics of vehicle testing can often feel like a minefield, especially with the ever-evolving technology in automotive lighting. For motorcycle MOT stations, particularly those like Dumfries Scooters in Dumfries, understanding the legality of aftermarket modifications is crucial. One area that frequently causes confusion is the fitment of combined LED rear lamp/stop lamp and indicator units. These units, which illuminate entirely for the stop/tail function and then flash amber in 50% of the unit for the indicators, are becoming increasingly popular. This article aims to provide a definitive answer regarding their acceptability during an MOT test, drawing on official guidance and explaining the underlying principles.
Understanding LED Combination Lamps
The world of LED lighting offers numerous advancements in brightness, efficiency, and longevity. However, not all innovative designs translate to road legality. It's essential to differentiate between acceptable and unacceptable types of LED combination lamps. The core principle governing their use is adherence to road safety regulations and the specific requirements for vehicle lighting as stipulated by the governing bodies.
Acceptable LED Combination Units
There are indeed types of LED combination lamps that are perfectly legal and acceptable for MOT testing. A prime example, often seen on certain Harley Davidson models, involves two rear lamps, one fitted on each side of the motorcycle. These units function as stop/tail lamps and also incorporate the direction indicators. Crucially, these are typically type approved, meaning they have met stringent safety and regulatory standards, including the required separation distances and visibility angles for both stop/tail and indicator functions. If your motorcycle is fitted with these, they should pass an MOT test, provided they are functioning correctly and meet all other lighting requirements.
Unacceptable LED Combination Units
The type of unit that has raised questions, and is generally not legal for use on public roads, is the single, centrally mounted lamp that combines stop/tail and both direction indicators. The primary reason for their rejection lies in their failure to meet minimum separation distances between the direction indicators. Road traffic regulations dictate specific spatial requirements for indicators to ensure they are clearly distinguishable from other lights and to avoid confusion for other road users. These regulations are in place to enhance road safety.
When such a centrally mounted, combined unit is fitted, it will likely fail an MOT test. While there isn't a specific, explicitly named "Reason for Rejection" for this exact type of unit, testers are required to fail it using a more general criterion. The applicable reason for rejection is: "The illumination of the lamp is affected by the operation of another lamp." This covers situations where the primary function of a lamp (e.g., stop lamp or rear position lamp) is compromised or altered by the activation of another function (e.g., the indicator). This applies equally to both the stop lamp and the rear position lamp functions within the combined unit.
Why the Separation Matters
The requirement for separation distances between vehicle lights isn't arbitrary. It's based on extensive research and practical considerations for how drivers and other road users perceive signals. For indicators, clear separation from brake lights and rear position lights is vital. When an indicator flashes, it needs to be distinct. If it's integrated into a unit that also functions as a bright stop lamp, the flashing amber light can be less visible or even masked, especially in daylight conditions. Similarly, the stop lamp's intensity should not be interrupted or confused by the flashing of an indicator. These rules ensure that signals are unambiguous and contribute to a safer driving environment for everyone.
When is a Lamp "Type Approved"?
Type approval is a certification process that ensures a vehicle component, such as a lighting unit, meets the prescribed technical and safety standards. For lighting, this often involves rigorous testing to confirm correct brightness, colour, beam pattern, and visibility angles, as well as compliance with photometric requirements. Components that are type-approved will usually bear specific markings or 'E' marks, indicating compliance with European standards. When a manufacturer states that their LED combination lamps are type-approved, it means they have undergone this official scrutiny and are deemed legal for use. Always look for these official markings on aftermarket parts.
What to do if you have Combined LED Units
If your motorcycle is currently fitted with the centrally mounted combined LED rear lamp/stop lamp and indicator units, it's advisable to have them replaced with compliant units before your next MOT test to avoid a failure. For owners of Dumfries Scooters, this means seeking out type-approved LED units that meet all the regulatory requirements for separation and function. This might involve reverting to a more traditional setup with separate indicator lamps or finding specific type-approved LED units designed to meet these regulations.
Table: LED Combination Lamp Comparison
| Feature | Acceptable Type (e.g., Dual-Unit) | Unacceptable Type (Centrally Mounted Combined Unit) |
|---|---|---|
| Mounting | Typically one unit on each side of the rear | Often a single unit mounted centrally |
| Functions | Stop, Tail, and Direction Indicator | Stop, Tail, and Direction Indicator |
| Legality | Generally Legal if Type Approved | Generally Not Legal |
| Reason for Failure (if applicable) | N/A (if functioning correctly and type approved) | "The illumination of the lamp is affected by the operation of another lamp." |
| Key Compliance Factor | Type Approval & Minimum Separation Distances Met | Fails to meet minimum separation distances; function interference |
Frequently Asked Questions
Q1: Are all LED rear lights illegal for motorcycles?
No, not all LED rear lights are illegal. Type-approved LED units, especially those with separate housings for stop/tail and indicators, or dual-unit setups that meet separation requirements, are perfectly acceptable.
Q2: What should I do if my motorcycle has a single, central LED rear light combining all functions?
You should consider replacing it with a compliant unit before your MOT test to avoid a failure. Consult with your local MOT station or a reputable mechanic for advice on suitable replacements.
Q3: How can I tell if an LED light unit is type-approved?
Type-approved components typically carry specific markings, often referred to as 'E' marks or other certification symbols, indicating compliance with relevant standards. Check the product packaging or the unit itself for these markings.
Q4: Does the colour of the LED indicator matter?
Yes, direction indicators must be amber. The stop/tail light function should be red. Combined units must ensure these colours are distinct and do not cause confusion.
Q5: Where can I find more information about MOT testing requirements?
For definitive information, you can refer to the official guidance provided by the Driver and Vehicle Standards Agency (DVSA). You can also send specific queries to [email protected].
Ensuring your motorcycle's lighting complies with MOT regulations is a key part of maintaining its roadworthiness. By understanding the difference between acceptable and non-compliant LED combination units, owners and testers can navigate these requirements with confidence. For businesses like Dumfries Scooters, staying informed about these critical compliance issues is paramount to providing excellent service and ensuring customer vehicles pass their tests without unnecessary hassle.
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