S. 207, a bill to enhance tribal road safety, would revise environmental regulations that are applied to certain highway infrastructure projects on Indian reservations. Those projects are administered by the Department of the Interior and the Federal Highway Administration and are funded from the Highway Trust Fund. Specifically, the bill would permit certain projects that address the safety of roads and bridges to be eligible for a different standard of environmental review, known as a categorical exclusion. The bill also would permit the Department of Transportation to delegate the responsibility for determining whether projects are eligible for expedited review to the tribes.