Fog is a major environmental issue in winter confronting the provinces of Punjab and Sindh in Pakistan. It incurs a considerable loss of life and the economy due to road accidents, traffic impasses, and cancellation or delay of air services. Pakistan meteorological department forecasts and updates fog weather conditions or fog status on their website https://nwfc.pmd.gov.pk/new/fog-motorways.php, which helps plan your trips.

What is Fog?

Fog is a meteorological phenomenon caused by tiny water particles and influenced by surface conditions. It is essentially a cloud close to ground level that reduces visibility.

Classification of Fog

Fog is classified as shallow if visibility is more than 500 meters, moderate if visibility is between 200 meters to 500 meters, and dense if visibility is less than 200 meters.

Types of Fog

The type of fog depends upon the scientific phenomenon which causes fog. Different types are Radiation fog, Advection fog, Evaporation fog, industrial fog, and valley fog. Radiational cooling of the surface reduces air temperature to its dew point temperature. Consequently, the reduced ability of air to hold moisture causes condensation or fog. Radiation fog requires a stable environment and a clear sky for development; as the sun rises, radiation fog dissipates due to warm ground.

Fog vs Mist

Both mist and fog develop due to the suspension of water droplets; the difference is in obscurity level. By definition, more than 1000ms visibility level is mist, and less than 1000ms visibility is fog.

How can you prevent accidents from the fog?

Fog weather conditions are hazardous due to limited or no visibility. It occurs during the winter season, starting from December to February. Visibility during winters remains more than 1000 ms, though, during the dense foggy days reduces to 200 ms or even 50 ms making it dangerous for driving. Visibility in lower Punjab remains much better compared to upper Punjab during fog weather.

Precautionary measures before travelling during fog

• The phenomenon of fog is localized and can create impromptu challenges while travelling. Therefore, it is necessary to plan your trips well in advance depending on the meteorological department’s fog prediction about the frequency and density of fog on the motorway or on your route.
• While planning your visit, adjust your travelling time to avoid extreme fog weather days and hours.
• Foggy conditions cause traffic congestion or roadblocks, so keep consulting the traffic conditions on your route.
• It is risky to cover long distances in one go during fog due to shorter days. Orientate yourself with your planned route and identify rest areas where you can stay during hours of dense fog. A journey of four to six hours in one day is safe to avoid fog on motorways or roads during fog weather
• Before travelling, check your vehicle mechanically and make sure the headlights and fog lights are working.

Safe Driving Tips

Driving in fog is akin to driving with a blindfold – notwithstanding your driving expertise, one should stay vigilant and adhere to safety tips for driving in fog weather conditions.

• Use a high beam. The use of headlights is of paramount importance while driving in foggy weather. Perhaps headlights are the only visible thing to an oncoming vehicle. Always use dipped headlights instead of high beams because fog tends to reflect the light to you and further reduces visibility due to high beams.
• Keep on the left edge of the road. When visibility drops considerably, keeping a sense of your surroundings becomes difficult. To avoid the risk of going astray and driving into adjacent or onrushing traffic, always use the left edge of the road as a guide.
• Don’t switch your lane. To determine the cars coming from behind you is difficult. Therefore, lane discipline assumes more importance while driving during fog.
• Always drive slowly during fog. Keeping an eye on the speedometer will help you in checking your speed. Slow driving will help you come to an easy stop if you suddenly confront a stopped vehicle or a person/ animal who is crossing the road.
• Never apply sudden breaks. It is probably the most crucial driving precaution during foggy conditions. It may result in another car rear-ending you making things worse for the other traffic on the road. Most accidents on motorways or highways happen due to sudden breaks where several vehicles bump into each other, causing fatal casualties.
• Keep your distance from other cars. Most drivers rely on the tail lights of vehicles in front of them for guidance. The inherent problem with this approach is a short reaction time if the car moving ahead varies its speed or applies sudden breaks. Therefore, keeping a safe distance from other vehicles will reduce the risk of accidents while driving in foggy weather conditions.
• Use Windsheild wipers. Moisture in the fog causes a glimmer on the windshield, further impairing your vision and creating difficulties to see.
• Turn on the defroster of your vehicle. Fog can cause condensation inside your car, which results in foggy windows. If you don’t switch on the heater, condensation on windows will become thick, rendering your vision impaired completely. To avoid such a situation, use the demisting feature of your vehicle or turn on the heater.

Finding Help

Pakistan Meteorological Department has a sub-branch named the National Weather Forecasting center, which provides updates about fog on motorways https://nwfc.pmd.gov.pk/new/fog-highways.php. National Highways and Motorway Police authority has also made endeavours to facilitate passengers in planning their journeys. They have started to issue a fog journey planner, which can be very helpful in avoiding dense foggy days/ times.

Key Take Aways

• Stay abreast with various measures taken by the Government or concerned authorities to forecast or update the frequency and density of the fog.
• Plan your trips in complete detail and well in advance based on the available information.
• Notwithstanding your driving skills, be vigilant while driving in foggy conditions and take extra measures to adhere to safety tips for driving in fog weather.
• Make an utmost effort to avoid travelling in foggy conditions or at least drive in such hours of the day when fog density is either shallow or moderate.