Annual Tsukuba Marathon will be held on November 25th, therefore there will be traffic restrictions (and traffic jam) at various places in Tsukuba.
The running route includes Higashi-Odori Blvd right in front of KEK, which makes it impossible to come in and out through main gate of KEK by car between 9:15 and 11:15.
So KEK leaves the south side gate near the soccer field (South of Gym and tennis court) open for the duration.
Recommended path to come in or out of KEK will be found in https://www2.kek.jp/imss/notice/assets/2018/11/16/map2_2018.pdf
If you need to come in and out of KEK on the day, we recommend you to do so before 9:15 or after 11:15.