Dense winter fog has settled over large parts of north India, transforming highways and busy city roads into streams of white mist. In these challenging conditions, drivers of four-wheelers are discovering the practical power of yellow light.
The Science Behind Yellow Light in Fog
Professor Ghan Shyam Singh Saini, a Physics professor at Panjab University, explains the phenomenon clearly. "Fog droplets scatter shorter-wavelength light," he says. "This means white and blue-rich LED beams often bounce back toward the driver, creating dangerous glare. Yellow or amber light has a longer wavelength. It scatters less and enhances contrast significantly."
This scientific advantage makes lane markings and upcoming vehicles much easier to spot during foggy conditions. Despite this clear benefit, most modern four-wheelers now come equipped with bright white LED systems. These systems frequently worsen glare rather than reduce it.
Drivers Adapt Despite Regulatory Limits
Caught between reduced visibility and strict regulations, many motorists are finding quiet ways to adapt. Some drivers switch on factory-installed fog lamps. Others add auxiliary lights to their vehicles. A common solution involves simply applying yellow film over existing lamps.
Seasoned drivers on routes between Chandigarh and the fog-prone belts of Punjab and Haryana are taking practical steps. They are doing more than just complaining about poor visibility. Many replace their factory fog lamps with yellow-preferred units. Others install auxiliary lights on bumpers or bonnets. Drivers on tighter budgets often apply yellow film to existing fog lamps or headlamp visors.
Real-World Experiences from Commuters
Several drivers confirm these adaptations work in daily practice. Mohik Sethi, a Chandigarh resident who regularly commutes to his hometown Ferozepur, shares his experience. "It may not be strictly allowed," he admits, "but in dense fog, white LEDs just bounce back at you. Yellow filters or auxiliary amber lights at least give you something to see."
Arshveer Gill, a Malerkotla resident living in Chandigarh, recounts a traffic stop. "I was stopped by Chandigarh traffic police," he says. "After telling them the auxiliary lights would stay covered within city limits, I was let go."
Cost and Sourcing Considerations
Financial factors heavily influence driver choices. Basic auxiliary lights typically measure 3 to 4 inches with multiple small LED chips. These cost a few thousand rupees but offer limited beam control.
More effective systems usually measure 4 to 5 inches with higher-output LEDs. These cost several thousand rupees. Premium multi-mode units with better beam patterns can run into tens of thousands.
Many drivers report sourcing higher-end lights through friends or relatives in Australia and the United States. These lights are designed specifically for fog and off-road use. Cheaper local options often lack consistency and durability according to users.
Legal Framework and Enforcement
Traffic authorities consistently warn that unauthorized lighting modifications remain illegal under motor vehicle rules. This applies whether the modifications are used or merely fitted to vehicles.
Rules for Auxiliary and Fog Lamps
Under the Motor Vehicles Act (1988) and Central Motor Vehicles Rules (CMVR), specific regulations govern vehicle lighting:
- All lighting devices must meet approved technical standards and colors
- Only white or amber/yellow are permitted for forward-facing lights
- Improper modifications that change original lighting specifications are illegal alterations
- Such modifications require certification and approval by transport authorities before registration
- Vehicles may face challans or require removal of non-compliant lighting
- A vehicle typically permits a maximum of 4 headlights including auxiliary/fog lamps
- Colors like blue, red, or green are prohibited for non-emergency vehicles
Official Police Statement
Sumer Pratap Singh, SSP Traffic for Chandigarh Police, provides clear guidance. "Any modification in a vehicle's lighting system is allowed only if carried out before registration and inspected at that stage," he states. "Auxiliary lights or additional lamps fitted after registration are not permitted if they violate prescribed norms. Even if such lights are covered or not in use, installation itself can attract action if it does not comply with rules."
Traffic police actively challenge vehicles for improper lighting. They pay particular attention to auxiliary and high-intensity LED lamps that can blind oncoming traffic. Authorities insist all lighting usage must follow prescribed standards for road safety.
