State and federal governments are looking to MBUF as a potential replacement for the fuel tax because the way we currently fund transportation is not sustainable. Vehicle fuel efficiency has improved dramatically since the fuel task was introduced over 100 years ago. Vehicles can go farther on less fuel or none at all. Though this has been great for our wallets and the environment, increased fuel efficiency has presented a challenge for the transportation system that depends on taxes collected per gallon. As vehicles become more fuel efficient, they contribute less revenue to building and maintaining roads, yet continue to contribute to wear and tear as well as congestion. A MBUF system is one alternative to the existing fuel tax to ensure that our transportation system receives the necessary funding for future generations.