A bill to amend title 54, United States Code, to provide that State law shall apply to the use of motor vehicles on roads within a System unit.

This bill (S 4560) changes the law to require that state traffic laws apply to motor vehicle use on roads within National Park System units (like national parks and monuments). It directly affects park visitors and operators who drive vehicles on park roads. The key provision replaces federal vehicle regulations with the specific traffic laws of the state where the park is located, including rules for off-highway vehicles defined by that state. Violating these state laws on park roads would be prohibited. The bill does not create new restrictions but shifts enforcement authority to the states.