Every time a new industry is born. The economy will expand like crazy. Create new jobs instead of building wealth for the empire and leapfrog development.
This time is the same as well. The Empire received an invaluable economic benefit. The first is that the businessmen have invested in building a car factory. They were causing tens of thousands of people to work—citizens from local regions walking into the capital to find a job.
Now the capital's population exceeded 1 million people. With such a population, only the Chang'an Capital of Datang Region was comparable.