About half a million students sat the college entrance exam across the country Thursday, South Korea's most important annual academic event during which airplane takeoffs and landings will be temporarily banned for noise control.

A total of 504,588 high school seniors, graduates and others signed up to take this year's state-administered College Scholastic Ability Test, a nine-hour, five-session exam that began at 1,279 test sites nationwide.

For the first time since the onset of the COVID-19 pandemic in 2020, CSAT takers with confirmed or suspected COVID-19 symptoms are allowed to take the test in the same room as others without the virus.

In the three previous consecutive CSATs since the pandemic, students with COVID-19 had taken the exam in separate rooms.

Mask-wearing, which had been mandatory for CSAT takers for the past three years, was also lifted for this year, although those with confirmed or suspected coronavirus symptoms are strongly recommended to wear a mask to prevent infections.

Exam takers with COVID-19 are also recommended to move to separate rooms to eat during the lunch break.

The CSAT, held on the third Thursday of November each year, is one of the nation's most important academic events, deemed the culmination of years of hard work for many students anxious to enter top universities.

Results from the once-a-year test are widely regarded by students and parents as one of the major factors determining one's university entrance and career path throughout their lifetime.

To control noise during the listening evaluation of the English test session, all aircraft takeoffs and landings will be prohibited between 1:05 p.m. and 1:40 p.m. across the country.

All aircraft in flight, excluding those in emergency situations, must also remain in airspace at an altitude of 3 kilometers or higher during the restriction time. The operating schedules of 94 flights will also be adjusted during the period, the transportation ministry has said.

The morning rush hour for increased subway services in Seoul was expanded to cover 6 a.m. to 10 a.m. from the current 7 a.m. to 9 a.m. time period to help exam takers reach their test centers on time, while bus services were also enhanced.

Police cars and regional government officials also stood by to help tardy students reach their test sites on time. Government institutions and ward offices in Seoul began work an hour later than normal, starting at 10 a.m., to reduce traffic congestion.

The operating hours of South Korea's stock exchange and the foreign exchange market will also be delayed by an hour, starting at 10 a.m., officials said. (Yonhap)