I calculated this out 2 months ago: The US spent 416 billion dollars on roads in 2014 [1]. At 123 billion gallons of gas [2] and 44 billion gallons of diesel [3], that would require $2.50 worth of tax per gallon. Gas near me is $3.40 with a 60 cent tax so $1.90 short or 24%.

[0]: https://terrapass.com/product/personal-carbon-offset-grouped

[1]: https://www.bidnet.com/resources/business-insights/us-govern...

[2]: https://www.eia.gov/tools/faqs/faq.php?id=23&t=10#:~:text=In...

[3]: https://www.eia.gov/energyexplained/diesel-fuel/use-of-diese...