Presidential candidate for South Korea’s ruling party vowed to heavily invest in high-speed trains and reduce the commute time in the greater Seoul area to within 30 minutes.

Lee Jae-myung of the ruling Democratic Party announced Monday he will expand the construction of Greater Train Express commuter network of railways, subways and expressways to improve the access of Gyeonggi Province residents to Seoul and other parts of the province.

The announcement was made in Lee’s campaign event held to appeal to voters in Gyeonggi Province, home to 13.41 million people, or 25.9 percent of South Korea’s population.

Naming his vision as the “GTX Plus” project, Lee said his government will increase the speed of GTX Lines A, B and C spanning across Gyeonggi Province and Seoul while adding new routes on top of the three lines already in plan.

The GTX A line that is planned to connect Paju to Hwaseong in Gyeonggi Province would be extended to reach Pyeongtaek, while GTX C would be expanded to serve residents of Pyeongtaek and Dongducheon. The three lines of A, B and C will be upgraded to run at faster speeds, he added.

The presidential candidate also announced he would build three new GTX lines named D, E and F in the province. One of them will connect Gimpo and Hanam of Gyeonggi Province, while the two other lines run trains from Incheon to Pocheon, Gyeonggi Province, and from Paju to Yeoju of Gyeonggi Province.

Lee added the lines in the plan could be extended further, depending on demands of Gyeonggi Province residents in the future.

The ruling party nominee said he is additionally looking to extend some subway networks in place. He said his team was planning to extend Seoul’s subway lines 3, 5, 6, 7, 8 and 9 to more municipalities in Gyeonggi Province while speeding up the construction of the Capital Region Second Ring Expressway.

The candidate has been pushing to open a new airport in Suwon, Gyeonggi Province, and combine the two airports in the region -- Incheon International Airport and Gimpo International Airport -- into one.

Improving transportation access for Gyeonggi Province residents has largely been touted as a way to curb housing prices in Seoul and enhance the appeal of non-Seoul areas as residential and commercial hubs.

The ruling party nominee reiterated his vision to ease regulations on reconstruction projects but added he will provide additional benefits for Gyeonggi Province’s first-generation new towns like Bundang, Ilsan and Pyeongchon.

Lee’s announcement comes as his support rating remains unchanged for months, prompting the need for his campaign team to make bold promises and better appeal to voters.

His support rating has remained between 30 and 40 percent in polls for months, while that for his primary rival Yoon Suk-yeol of the main opposition People Power Party has fluctuated heavily in recent weeks.

Gyeonggi Province is touted as a powerhouse for Lee as he served as the governor for the province until officiating his bid for presidency last year. Maintaining dominance in the region is key to the candidate’s success in the upcoming election slated for March.

Lee vowed to differentiate his government from the Moon Jae-in administration with better policies and initiatives in an attempt to draw voters increasingly dissatisfied with the outcomes of the Moon government for the past four years.