What is the best alternative fuel to replace petroleum for the United States?

It's interesting to note that while fossil fuel combustion engines are being sought after, other alternatives like hydrogen fuel cells, natural gas or propane, and biofuels are simply not gaining traction and might be abandoned.

Since autonomous vehicles operate more efficiently than human drivers, it is anticipated that these robots will significantly reduce emissions of all kinds, regardless of the energy source!

The best alternative fuel to replace petroleum for the United States depends on various factors such as availability, environmental impact, infrastructure, and technological advancements. Some of the most promising alternative fuels include biodiesel, ethanol, hydrogen, natural gas, and electricity (for electric vehicles). Each has its advantages and limitations, and the optimal choice may vary depending on specific regional or national circumstances.