Though not popular in many areas of the U.S., road tolls are a common part of daily life in many Eastern cities and in cities around the globe. According to a new study by researchers at two California universities, the age-old question of whether tolls are more equitable than taxes has been answered, and tolls are the way to go, they say.

Based on a study of a 10-mile (16km) stretch of the 91 Express Lanes tollway, which features four lanes for the exclusive use of drivers pre-registered with transponders. The charges to use the reserved lanes are variable and based on demand and time of day, while the remaining lanes are free. By comparing the usage patterns with income levels and correlating that with the effects of tax or toll-based revenue generation on income, the study came to its conclusion.

The reason tolls are more equitable is that they impact poor less harshly than taxes. Because transport projects must be funded, there's no way to avoid needing either tolls or taxes, but the study bolsters the idea that usage-based payment is fairer than sales-tax-based payment, because flat-rate taxes form a larger portion of the total income for the poor compared to the wealthy, whereas the wealthier road uses are the predominant express-lane users, according to study data, reports Green Car Congress.

Historically, flat-rate charges such as sales taxes and road tolls have both been subject to the same criticism of regressiveness, or having a heavier impact on the poor than the wealthy. Proponents of the study's findings, however, think that in this case, the toll is less regressive since it is use-based, whereas the tax impacts the poor regardless of whether they own or drive cars.