Developers, led by PT Sarana Bali Dwipa Jaya, will start work on the project, called Bali Subway, in September, according to a government statement on Thursday.

The initial two stages of development will cost US$10.8 billion and will be completed by 2031, it said. The total cost will eventually rise to US$20 billion.

Heavy traffic to and from Bali’s international airport is a major pain point for tourists amid rising number of visitors post Covid-19 era travel curbs. Foreign tourist arrivals hit the pre-pandemic level of around 500,000 per month just last year.

The development is part of President Joko Widodo’s ambition to build more trains to ease traffic in Indonesia’s most congested cities. Just last year, he inaugurated two multimillion dollar railway projects connecting Jakarta with surrounding cities.