In one of the most hotly contested local races, the candidates for Seoul mayor have already outlined plans for safety reforms.
Incumbent Park Won-soon of the main opposition New Politics Alliance for Democracy said he will spend close to US$2 billion on safety measures that include renewing old subway cars and providing school buses for elementary schoolchildren.
Ruling Saenuri party challenger Chung Mong-joon wants to clean up the air in major subway lines, citing the critical levels of ultra-fine dust, mostly in the subway line No. 1.
The local elections will take place on June 4.