The M2 motorway from Lahore to Sheikhupura was closed for traffic for several hours on Wednesday due to dense fog, a day after a multi-vehicle collision near Sheikhupura left 20 people wounded.
The Tuesday's huge motorway pile-up involved 30 vehicles and led to precautionary measure on the following day.
When authorities closed M2 between Lahore and Sheikhupura there were massive traffic jams at the interchanges, especially in the Thokar Niaz Baig area in Lahore. People shared photos of stranded vehicles on social media.
The M3 from Lahore to Samandari was also closed due to fog.
The motorway police instructed people to use fog lights.
A dense fog has become almost daily occurrence in Punjab and Khyber Pakhtunkhwa plains causing traffic disruptions.
On Monday and Tuesday, sections of motorways M1, connecting Peshawar with Islamabad, M11, connecting Lahore to Sialkot, and M3 connecting Lahore to Multan were closed.
However, M2 was not closed on Tuesday and it caused the multi-vehicle collision.
Over 30 vehicles collided near Kala Shah Kaku in Sheikhupura on Tuesday morning.
Rescue officials said at least 20 people were injured, at least 10 of them requiring hospital treatment.
Besides fog, smog has also reduced visibility levels throughout cities, causing problems for commuters and leading to serious health issues such as flu, cough, throat infection, breathing problems, and chest pain.
According to doctors, more than 120 smog infections are being reported in the province on a daily basis.
Meanwhile, Pakistan Meteorological Department (PMD) says the foggy and smoggy conditions will stay on Wednesday across Punjab.