noun
national development arterial expressway
A formal legal term used in Japanese road law to designate the network of high-standard expressways planned and developed by the national government.
国土開発幹線自動車道は、全国的な高速道路網の基幹をなす。
The national development arterial expressway forms the backbone of the nationwide expressway network.
高速道路 is the general term for expressways, while 国土開発幹線自動車道 is a specific legal classification for nationally planned arterial routes.
Compound of 国土 (national land), 開発 (development), 幹線 (trunk line), and 自動車道 (motorway). The term was established in Japanese road legislation.