The government submitted a tax reform bill to the Diet Jan. 23 that includes a clause to continue the provisional higher rates imposed on auto-related levies for another 10 years, drawing opposition from the Democratic Party of Japan, which wants the higher rates that have been in place for more than 30 years abolished.

The DPJ's proposal would result in lower pump prices, but many local governments fear the loss of road-related tax revenues would deal a heavy blow to their coffers.

Here are questions and answers about road-related tax revenues and the provisional tax rates that have become the hottest bone of contention in the current Diet session: