Once a year, on Thursday before the third Saturday of November, the biggest test in South Korea called ‘suneung’ is held. On this day, every senior high school student and those who wish to enter college in Korea take this test. This year’s suneung, also known as the College Scholastic Ability Test (CSAT) as the official English term, was held last week on the 18th. Recently, BBC reported on suneung calling it “the world’s hardest” test.

While there may be different opinions on the CSAT questions being objectively the ‘world’s hardest’ (and believe from someone who took the test twice, it is hard), the difficulty of the exam lies more in how pressuring it is. Students who are in their 3rd and final year of high school prepare the entire year for the exam. Once the exam for the year is over, the countdown begins for the 2nd year high schoolers, although their new school year doesn’t start until March. Because the CSAT is held only once a year, you would have to wait another year if you missed or messed up the test. So it isn’t an exaggeration to say that one singular day of the test is what your entire 12 years of public education in Korea have led up to, and decides whether you get accepted to the college you want based on the scores.

Well aware of the magnitude and grave nature of the test, airplanes are not allowed to land or take off during the listening session of the English test, and police cars drive examinees in urgency so they could arrive at their exam site in time. Many city and province governments allocate more taxis and buses in town for the examinees. Not only government offices, but banks and schools delay their starting hours to 10am or later to keep from worsening the traffic. On the day of the test, the country is unusually quiet; there is tension in the air. As such, the whole country cooperates for the examinees to take their test in peace and their best conditions as possible.

Then what was the actual traffic like compared to the usual days on this year’s CSAT? We decided to see how traffic changed near the test locations. Most of the test locations are high schools, and test takers have to be at their testing rooms by 8:10, so we decided to find out each average travel speed of vehicles in a neighborhood in Gangnam district and one in Nowon district respectively, at 7:30. We then compared the speed with the average speed on usual Thursdays, during the same time period and in the same areas.


Traffic near exam locations in Gangnam district


Traffic near exam locations in Nowon district
The gif images above show the traffic change in vehicle travel speeds indicated by the colors. In both images, you can notice the evident difference in colors around the marked schools, all of which were exam locations this year. The roads that have yellow lines on typical Thursdays turned red on the test day, and the roads with green lines turned yellow.
This indicates the slowing of vehicle speed on roads surrounding the testing sites, from which we can infer that suneung caused more traffic.

This year, over 500,000 test takers took the CSAT, unlike last year, when the number had dropped below 500,000 and the exam date was pushed back to December for the first time in history due to COVID-19. Because such a high number of test takers all transport to their assigned exam places, the traffic jam near high schools shown according to our data in the early morning seems natural.

We wish all the students great results and best of luck in the rest of their application process.