The proposed amendment to the Missouri Constitution would require approval in a statewide vote and would expire after 10 years.
Proponents estimate the higher sales tax would raise nearly $8 billion over 10 years for transportation projects.
The measure would dedicate 10 percent of the extra revenue to local transportation needs and freeze the state’s gas tax rate while the higher sales tax was in effect.
The Missouri House Transportation Committee endorsed the measure Tuesday. The Senate Transportation Committee held a public hearing on a similar proposal last week.