Seoul now has a large number of bike paths along the banks of small creeks, and large rivers like the Han.
Even some of the extremely busy inner city roads have good segregated bike lanes.
Look carefully at the rider in red on the MTB (behind the blue rider)
He is wearing a mask to protect against air pollution.
this is very common in Korea.
The day the photo was taken the temperature was about 25 degrees, yet the majority of riders were wearing long sleeved jerseys, leggings (cycling pantyhose) and a significant percentage of the serious riders wore the pollution masks.
Because Koreans consider a white skin to be better than the tanned look westerners prefer.
A deep tan indicates you work in the outdoors which is usually a sign that you don’t have a good education and status.