It is named after Prussian explorer Ludwig Leichhardt who travelled a route in the 19th Century that roughly parallels today's highway.
highway | state highway | Princes Highway | Alaska Highway | Trans-Canada Highway | Jefferson Highway | New Zealand State Highway 1 | Ludwig Leichhardt | Highway to Heaven | Mexican Federal Highway | Federal Highway Administration | California Highway Patrol | New Zealand State Highway 6 | Minnesota State Highway 55 | Lincoln Highway | Stuart Highway | Hume Highway | Federal Highway | Controlled-access highway | Pacific Highway | North Carolina Highway 20 | National Highway Traffic Safety Administration | Interstate Highway System | Highway Patrol | Minnesota State Highway 32 | Minnesota State Highway 27 | Mexican Federal Highway 1 | North Carolina Highway 87 | New Zealand State Highway network | Highway 101 |