South Dakota lawmakers have approved the preparation of a document that will help explain to the public why a legislative committee recommended substantial increases in taxes used to support state and local roads.

A study committee last month recommended a 10-cent-a-gallon increase in the state gas tax, a 1 percent increase in the excise tax on vehicle sales, and a boost in the annual vehicle registration fee. That proposal will be considered by the legislative session that opens in January.

The Legislature's Executive Board agreed Monday to have legislative staff prepare a summary explaining how revenue has declined while the cost of building and maintaining roads has risen substantially.

The summary will be placed on the Legislature's Web site.