A combination of pollution and heavy fog affected countless road, rail and air passengers across northern China on Wednesday.

By 4:30 pm, 154 flights had been canceled at Tianjin Binhai International Airport, with another 120 delayed. A total of 450 flights were scheduled to arrive and depart during the day.

The city also closed all 20 freeways due to low visibility in the morning, although half were reopened at 2 pm, according to the local transportation commission.