The government works in cooperation with industry. Putting a timeline on something that's already happening is pretty simple and prevents the prisoner's dilemma

The government works in cooperation with industry. Putting a timeline on something that's already happening is pretty simple and prevents the prisoner's dilemma problem among competitors. Anyway, the government already controls tons of subsidies and regulations on the fuels and car industries, so it's not like there's a pure market signal to be had here.