Turning on side lights instead of full lights daytime running lights (DRL) often causes a decrease in the visibility of a car on the road, which directly affects the likelihood of an emergency during daylight hours. Drivers often mistakenly believe that illuminated “dimensions” perform the same safety function as bright LED strips, but the intensity of the luminous flux of these devices is not comparable. Understanding the physical differences and legal requirements is necessary for every motorist to avoid fines and, more importantly, not to become involved in an accident due to poor visibility.
The lighting technology of a modern car is a complex system where each element has a strictly regulated purpose and technical characteristics. DRL and dimensions are not just light bulbs, but elements that ensure traffic safety in different conditions. Confusion in their use often arises due to visual similarities in some operating modes or due to the design features of the headlights, when the same diodes can shine with different brightness. It is important to clearly understand that Side lights are not intended to indicate a vehicle in daytime traffic., and their use as a replacement for DRLs is a gross violation.
Physical differences in lumen output and design
The main difference lies in the strength of the luminous flux, which is measured in lumens. Daytime running lights must produce between 400 and 800 lumens of light to be clearly visible even in bright sunlight. At the same time, side lights have a significantly lower power, usually not exceeding 50-100 lumens, since their task is to indicate the dimensions of a stationary or slowly moving vehicle at dusk or at night.
- 💡 Glow intensity: DRLs shine 5-8 times brighter than their dimensions, which allows other road users to notice the car at a distance of up to 400 meters.
- 💡 Scattering Angle: The running lights have a more directional beam of light, oriented forward, while the headlights shine more widely, but weakly.
- 💡 Color Temperature: DRLs are strictly regulated to have a white color, while the dimensions may have a yellowish tint, especially if incandescent lamps are used.
Structurally, these devices may also differ. In modern cars they are often used LED modules, where the same LED strip can operate in two modes: at 100% power as DRLs and at 10-15% as dimensions. However, in budget models or used cars there are still conventional incandescent lamps of dimensions that are physically incapable of producing the necessary brightness for daytime designation.
⚠️ Attention: Installing too bright lamps in side lights to simulate DRLs can lead to dazzling oncoming drivers and rapid failure of the plastic headlight lens due to overheating.
Legal requirements and traffic rules
Traffic rules clearly regulate the use of lighting devices. According to clause 19.5 of the traffic rules, during daylight hours all moving vehicles must have their lights turned on. low beam headlights or daytime running lights. The use of side lights in the daytime instead of the specified devices does not comply with the requirements of the rules and is regarded by inspectors as a violation.
The legislation is based on the principle of maximum visibility of the car. DRLs were introduced as a mandatory element specifically to reduce accidents during the day. Statistics show that cars with running lights or low beams on are 20-30% more noticeable than cars with only their headlights on. Therefore, the legal requirement is aimed at preserving the life and health of road users.
There is a common misconception that if a car is equipped with automatic DRLs, then you can ignore other rules. However, if your car does not have DRLs, the only legal alternative is to turn on low beam headlights.
Is it possible to drive during the day with only dimensions?
The answer to this question is clear: driving during the day with only the side lights on is prohibited. The dimensions do not provide sufficient contrast of the car against the background of the road surface and the environment. In conditions of bright sun, fog or rain, a car with illuminated lights merges with the flow, and it becomes extremely difficult to notice it.
- 🚗 Security: The risk of an accident when using traffic lights during the day increases many times over, since drivers behind and in front may simply not see your car.
- 🚗 Penalties: For the absence of switched-on DRLs or low beams during the day, a fine is imposed, which is issued under the relevant article of the Code of Administrative Offenses.
- 🚗 Insured events: In the event of an accident, if it is proven that the car was poorly visible due to improper use of lighting devices, the insurance company may apply a recourse claim.
Some drivers justify the use of dimensions with the desire to save the life of low beam lamps or batteries. However, modern halogen and LED lamps last quite a long time, and the car's generator can easily cope with the load. The savings in this case do not justify the risk to life and monetary losses due to fines.
⚠️ Attention: Attempts to deceive the system by gluing part of the headlight or installing non-standard bright lamps in the dimensions can lead to refusal to pass a technical inspection and problems during registration.
Technical nuances of the operation of lighting devices
In the electrical circuit of a car, the DRL and clearance circuits are often separated. Daytime running lights typically turn on automatically when the engine is started and turn off when the low beams are turned on or when the vehicle is parked. The dimensions are controlled manually by the driver through a switch on the steering column or instrument panel.
☑️ Checking the health of the lighting system
There are systems where the functions are combined. For example, in some models Volkswagen or Skoda The outer segments of the low beam lamp burn at full intensity like DRLs, and when the headlights are turned on, other threads or segments begin to burn. In such cases, it is important that the glow is bright enough during daylight hours. If the driver forcibly turns on only the headlights, the brightness drops and the car no longer meets safety requirements.
The wiring deserves special attention. Installing additional DRLs requires proper connections via relays and fuses. Installation errors can lead to a short circuit or incorrect operation of the on-board computer, which may perceive LEDs as burnt out lamps due to low power consumption.
Comparison table of characteristics
For clarity, let’s consider the main parameters that distinguish these two types of lighting devices. The table will help you quickly navigate the technical requirements and functional purpose.
| Parameter | Daytime running lights (DRL) | Side lights |
|---|---|---|
| Main function | Designation of a car in motion during the day | Indication of parking area or at night |
| The power of light | 400–800 lm (high) | 40–100 lm (low) |
| Operating mode | Automatically when the engine is running | Switched on manually by the driver |
| Visibility | High (up to 400 meters) | Low (up to 100 meters) |
The table shows that the difference in characteristics is significant. An attempt to use one device instead of another violates the logic of the car's light alarm. Car manufacturers carefully calculate the optics so that the light output does not blind oncoming drivers, but is clearly visible in the daytime.
The history of DRL
Daytime running lights became mandatory in Scandinavian countries back in the 1970s due to specific weather conditions. Later, the experience was adopted by other European countries and Russia, where accident statistics decreased by 10-15% after the introduction of mandatory use of DRLs.
Frequent mistakes and myths of drivers
One of the most common myths is that dimensions “save battery life.” In fact, the difference in energy consumption between headlights and DRLs (especially LEDs) is minimal and does not affect the battery life of a modern car. The generator produces energy with reserve, and the load from lighting devices