Elon Musk’s tunnel construction company, The Boring Company, is planning to propose a new underground transport project in Riyadh. The idea is to help reduce traffic in the city by building a network of underground roads. This announcement comes just a day before Musk’s Tesla officially launches its electric vehicles in Saudi Arabia on April 10.

Riyadh is one of the fastest-growing cities in the world. Its population is expected to jump to nearly 10 million by 2030 (+35% in 8 years). With more people and cars on the road, the city is looking for smart ways to manage traffic and keep people moving efficiently.

Building roads underground is one such solution. It could ease congestion without taking up more space above ground. The Boring Company has already tested similar systems elsewhere — most notably in Las Vegas, where it built a tunnel system specifically designed for electric cars.

Earlier this year, The Boring Company also partnered with Dubai’s Roads and Transport Authority. They agreed to create a 17-kilometer underground route with 11 stations, capable of moving over 20,000 passengers per hour. If successful, the project will expand into a city-wide system called the Dubai Loop.

Riyadh could be next in line for this type of high-tech underground transport system — if Saudi officials approve the plan.