Modifies provisions relating to transportation funding

HB 1409 modifies Missouri's transportation funding by changing fuel tax rates for various vehicle fuels. It sets tiered tax rates that increase over time (e.g., compressed natural gas starts at 5 cents per gallon until 2019, rising to 17 cents after 2024) and creates a new "Motor Fuel Tax Fund of 2021" to finance state road and bridge projects. The bill also establishes a refund program for businesses that pay the tax but use fuel for exempt purposes (like heating), requiring them to submit detailed claims with proof of fuel use. This directly affects all consumers and businesses purchasing motor fuel, natural gas, propane, or electricity for vehicles, with tax rates and refund rules applying statewide.