National highway - kokudo

Japanese: 国道 - こくどう

Among the roads under the Road Act (Act No. 180 of 1952), those designated by the Minister of Land, Infrastructure, Transport and Tourism as being involved in the construction and operation of in some way by the government due to their role in the national road network are national expressways and general national highways. General national highways are designated as routes that make up the national trunk road network and connect cities that are politically, economically, or culturally important, while national expressways are designated as expressways that are particularly important to the interests of the nation. However, the government does not manage all routes and sections at its own expense. Management here is a term used in the Road Act to collectively refer to new construction, reconstruction, maintenance, repair, and other management (same below).

[Iseda Mutsumi]

National highway

Ordinary national highways are divided into direct national highways (designated sections) and auxiliary national highways (outside of designated sections). This is because the old Road Law before World War II had a principle that, except for exceptional cases where the national government would build or renovate at its own expense (such as routes connecting Tokyo City with Jingu Shrine, prefectural offices, and division headquarters locations), all roads were managed by prefectures (governors) as national institutions, and the costs were to be borne by the prefectures even if the national government provided subsidies, and this principle was inherited in the new Road Law after the war (when prefectures were no longer national institutions). The former later became direct national highways and the latter auxiliary national highways. Auxiliary national highways also account for a larger proportion of the total length of ordinary national highways (as of April 2011, 39,606.4 km out of the total length of 67,297.5 km). The existence of auxiliary national highways, which are national highways but are managed by prefectures at their own expense, is justified by the recognition that the main beneficiaries are the residents along the route, but this does not match the requirements for a national highway (a route that constitutes a national trunk road network and connects important cities) or the actual usage (the percentage of through traffic that does not start and end within the same prefecture is by no means low). Therefore, through several amendments to the Road Law, corrections were made in the direction of strengthening the involvement of the national government in terms of management and cost burden, and the national government is now responsible for the construction and reconstruction of both directly managed and auxiliary national highways, but not only is the responsibility of the prefecture (or designated cities; the same applies below) still in charge of the maintenance, repair, and other management of auxiliary national highways, but in terms of cost burden, the prefecture is responsible for one-third of the construction and reconstruction of directly managed national highways and 4.5/10 of the maintenance and repair costs, while the prefecture is responsible for half of the construction and reconstruction of auxiliary national highways and the full amount of maintenance and repair costs. Although they are called national highways directly managed by the prefectures, there is persistent criticism from various quarters that they impose heavy burdens on prefectures in terms of both construction and reconstruction as well as maintenance and repair.

Among general national highways, there are expressways, including the Honshu-Shikoku Bridge, called general national highways for motor vehicles. Many of them are managed as direct national highways that do not impose tolls, but some (including the Honshu-Shikoku Bridge) are managed by expressway companies as general toll roads on behalf of the government. Unlike expressways, which will be described later, general toll roads do not apply the pool system, so they calculate their income and expenditure individually and are opened to the public free of charge when the debt repayment is completed. However, for routes that do not expect a large amount of traffic, the individual profit-making system means that the tolls will exceed the users' ability to bear, which leads to a vicious cycle of further decreasing the traffic. Therefore, a new method called the merged construction method has been applied to such routes. The government will bear the cost of acquiring the land and part of the construction, and the company that is subject to the toll will only bear the remaining construction and subsequent management. This method is also being introduced to expressways.

[Iseda Mutsumi]

National Expressway

Expressways are roads used for high-speed traffic by automobiles that were added to the list of national highways by the amendment of the Road Law in 1957 (Showa 32). Based on the Expressway Law (Law No. 79 of 1957), the planned routes, which are the National Land Development Trunk Expressways plus some routes determined by the Minister of Land, Infrastructure, Transport and Tourism, are developed in sequence based on the basic plan and development plan decided by the Minister of Land, Infrastructure, Transport and Tourism after deliberation by the National Land Development Trunk Expressway Construction Council (for National Land Development Trunk Expressways and the National Land Development Trunk Expressway Construction Council, see the chapter on "High-standard Trunk Roads"). After the privatization of the four road-related public corporations, expressway companies are to construct, reconstruct, maintain, repair, recover from disasters, and otherwise manage new routes based on agreements with the Japan Expressway Holding and Debt Repayment Agency, and to lease existing routes from the agency and maintain, repair, recover from disasters, and otherwise manage them, all under the toll road system. However, for some of the routes and sections for which development plans had been decided, it was expected that the company would not undertake the project due to the bleak outlook for profitability. In order to make it possible to develop even such routes and sections, the government and ruling party at the time decided to introduce a development method called the "new direct method" during discussions on drafting privatization legislation, and institutionalized this by amending the National Expressway Act.

The new direct management method refers to expressways that are developed by the national government at the expense of the relevant local authorities (local governments are responsible for one-fourth of the costs of new construction, reconstruction, maintenance, and repairs, but this share is actually covered by the automobile weight tax), and are made available to use free of charge. Of the planned routes for which development plans have been decided, the new direct management method applies to 865 km of the 9,428 km of planned expressways (as of March 31, 2011), but the application of this method is subject to approval by the Construction Council, where Diet members have a strong voice, so it is expected that this number will increase in the future.

[Iseda Mutsumi]

High-standard trunk road

High-standard trunk roads are expressways that are positioned within a national trunk transportation network to accommodate high-speed automobile traffic. They consist of expressways and general national highways that are expressways.

The origin of the high-standard trunk road is the National Land Development Longitudinal Expressway, which was ordered to promote the construction of the National Land Development Longitudinal Expressway by specifying the planned route through the National Land Development Longitudinal Expressway Construction Act (1957) and subsequent individual construction legislation (both of which were bills enacted by the Diet). The national government took over this with the addition of some new planned routes through the Expressway National Highway Act (1957), and constructed and managed them as roads under the Road Act. After that, the government decided that the development of these roads should be promoted as an organic and integrated expressway network that looks at the entire country, rather than as individual routes, and repealed the previous bills enacted by the Diet and enacted the National Land Development Trunk Highway Construction Act (1966), changing the name to National Land Development Trunk Highway. With the exception of a few, these roads, which are covered by both the National Land Development Trunk Highway Act and the Expressway National Highway Act, are required to have their basic plans and development plans, including the routes added under the latter act, approved by the National Land Development Trunk Highway Construction Council (half of whose members are Diet members), in accordance with the purpose of the former legislation.

Whether it was the Longitudinal Expressway or the Trunk Expressway, as can be seen from the fact that both of them have the word "National Land Development" in their names, their significance was placed on national land development and regional development rather than transportation. Due to this background, the Fourth Comprehensive National Development Plan (1987) named expressways and general national roads designated by the Minister of Land, Infrastructure, Transport and Tourism (the latter does not involve the Construction Council) as high-standard trunk road networks, and positioned them as forming the core high-speed land transportation network that will form the backbone of the country. The high-standard trunk road network concept of the Fourth Comprehensive National Development Plan was planned to be a network of about 14,000 kilometers in total, of which 11,520 kilometers were expressways and about 2,480 kilometers were general national roads and general roads and motorways (including 180 kilometers of the Honshu-Shikoku Bridge), and was inherited as it was in the Grand Design for the National Land in the 21st Century (1998), which succeeded the Fourth Comprehensive National Development Plan. Of this total, 8,663 kilometers are national expressways and 1,206 kilometers are national highways for motor vehicles only (as of September 1, 2011).

[Iseda Mutsumi]

[Reference item] | Highway | Road

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

Japanese:

道路法（昭和27年法律第180号）上の道路のうち、全国的な道路網に占める役割から国がその建設・運営に何らかの形で関与するとして国土交通大臣が指定するもので、高速自動車国道と一般国道とからなる。一般国道は全国的な幹線道路網を構成し、しかも政治上・経済上・文化上重要な都市を結ぶ路線などが、また高速自動車国道はそのなかでも国の利害にとくに重大な関係を有するものが、それぞれ指定される。とはいえ、すべての路線・区間につき管理を国が自らの負担で行うわけではない。ここでいう管理とは道路法上の用語で、新設・改築と維持・修繕その他管理を総称する（以下同様）。

［伊勢田穆］

一般国道

一般国道は、直轄国道（指定区間）と補助国道（指定区間外）からなる。これは、第二次世界大戦前の旧道路法に、例外的に国が自らの負担で新設・改築を行うもの（東京市と神宮・府県庁ならびに師団軍司令部の所在地などとを結ぶ路線など）のほかは、すべて国の機関としての府県（知事）が管理し、その費用は国が補助金をつけるにしても府県の負担とするという原則があって、この原則が戦後の（都道府県が国の機関ではなくなった時代の）新道路法にも継承されたことによる。前者が後に直轄国道、後者が補助国道となった。一般国道総延長に占める割合も補助国道の方が大きい（2011年4月の時点で、総延長6万7297.5キロメートル中の3万9606.4キロメートル）。国道でありながら都道府県が自らの負担で管理する補助国道の存在を根拠づけるのは、その主たる受益者は沿線住民であるとする認識であるが、それは国道の要件（全国的な幹線道路網を構成し、しかも重要な都市を結ぶ路線）とも、またその利用の実態（同一都道府県内に起点と終点をもたない通過交通の割合はけっして低くはない）とも合致しない。そこで、道路法の数次にわたる改正によって、管理と費用負担の面で国の関与を強める方向で是正がなされ、新設・改築については直轄国道・補助国道とも国の責任となったが、補助国道の維持・修繕・その他管理の責任は依然として都道府県（または政令指定市。以下同様）にあるばかりでなく、費用負担の面では直轄国道であっても新設・改築では3分の1を、維持・修繕でも10分の4.5を、補助国道であれば新設・改築でも2分の1を、維持・修繕では全額を都道府県が分担する。直轄国道といっていながら新設・改築と維持・修繕の両面で都道府県に多額の負担を強いることに、各方面からの批判は根強い。

　一般国道には一般国道自動車専用道路という名の、本州四国連絡道路を含む、高速自動車国道とは別の自動車専用道路が存在する。その多くは通行料を課さない直轄国道として管理されるが、一部（本州四国連絡道路を含む）は国にかわって高速道路会社が一般有料道路として経営する。一般有料道路は、後述の高速自動車国道とは違ってプール制は適用されないので、個別に収支を計り、債務の償還が完了した時点で無料開放される。ただ、通行量に多くを見込めない路線は、個別採算制では料金は利用者の負担力を超えることになり、それが通行量をさらに減少させるという悪循環に陥る。そこで、その種の路線には合併施工方式という名の新方式が適用されることとなった。用地の取得と工事の一部を国の負担で行い、料金の対象となる会社の負担を残りの工事とその後の管理に限るわけである。この方式は高速自動車国道にも導入されようとしている。

［伊勢田穆］

高速自動車国道

高速自動車国道は、道路法の1957年（昭和32）改正によって国道に加えられた自動車による高速交通の用に供する道路であって、高速自動車国道法（昭和32年法律第79号）に基づき、国土開発幹線自動車道に若干の国土交通大臣の定める路線を加えた予定路線のうちから、国土開発幹線自動車道建設会議の議を経て国土交通大臣が決定する基本計画・整備計画に基づき順次整備される（国土開発幹線自動車道と国土開発幹線自動車道建設会議については「高規格幹線道路」の章を参照）。この種の道路は、道路関係四公団の民営化後は高速道路会社が、新設路線は日本高速道路保有・債務返済機構との協定に基づき新設・改築および維持・修繕・災害復旧・その他管理を、既設路線は機構から借り受けて維持・修繕・災害復旧・その他管理を、いずれも有料道路方式で実施することになっている。しかし、整備計画の決定された路線・区間には採算の見通しの厳しさから会社が事業化を引き受けないと予想されるものもあり、当時の政府・与党はそうした路線・区間であっても整備を可能にすべく、民営化立法の法案化の協議のなかで「新直轄方式」と名づける整備方式を導入することとし、高速自動車国道法を改正して制度化した。

　新直轄方式とは、国が関係する地方当局の負担を得て整備し（地方の負担割合は新設・改築と維持・修繕とも4分の1。ただしその負担分は実際には自動車重量税の配分によって補填(ほてん)される）、高速自動車国道でありながら無料で利用に供するものをいう。整備計画の決定した予定路線のうちで新直轄方式の適用される区間は、高速自動車国道予定路線9428キロメートル中の865キロメートルであるが（2011年3月31日現在）、この方式の適用は国会議員の発言力の強い建設会議の議を経る定めになっているので、今後さらに増えると予想される。

［伊勢田穆］

高規格幹線道路

高規格幹線道路とは、自動車による高速交通に対応するための、全国的幹線交通網のなかに位置づけられた自動車専用道路をいう。高速自動車国道と、一般国道の自動車専用道路の二つからなる。

　高規格幹線道路の母体は、国土開発縦貫自動車道建設法（1957）とその後の個別の建設立法（いずれも議員立法）によって国に予定路線を明示して建設の推進を命じた国土開発縦貫自動車道にある。これを国は、若干の新たな予定路線を加えて高速自動車国道法（1957）をもって引き継ぎ、道路法上の道路として建設・管理した。その後政府は、その整備は個別の路線ごとにではなく国土全体を見通した有機的・一体的な高速道路網として推進すべきだとして、それまでの議員立法を廃止して国土開発幹線自動車道建設法（1966）の立法化を図り、名称も国土開発幹線自動車道に改めた。一部を除き国土開発幹線自動車道法と高速自動車国道法との二重の籍を有するこれらの道路は、前者の立法の趣旨から、後者の法律で追加された路線も含めて、基本計画と整備計画は国土開発幹線自動車道建設会議（国会議員が委員の半数を占める）の議を経なければならないことになっている。

　縦貫自動車道にせよ幹線自動車道にせよ、いずれも国土開発という語を冠することからもわかるように、その意義を交通というよりは国土開発・地域開発に置いていた。そうした経緯もあって、第四次全国総合開発計画（1987）が高速自動車国道に一般国道中の自動車専用道路のうちから国土交通大臣の指定する路線（後者には建設会議は関与しない）を加えたものを高規格幹線道路網と命名し、国土の骨格となる基幹的な高速陸上交通網を形成するものとして位置づけた。「四全総」の掲げる高規格幹線道路網構想は、全体で約1万4000キロメートル、うち高速自動車国道は1万1520キロメートル、一般国道自動車専用道路は約2480キロメートル（本州四国連絡橋180キロメートルを含む）からなるネットワークを計画し、四全総の後継の「21世紀の国土のグランドデザイン」（1998）にもそのまま引き継がれた。このうち高速自動車国道は8663キロメートル、一般国道自動車専用道路も1206キロメートルがすでに供用済である（2011年9月1日現在）。

［伊勢田穆］

[参照項目] | 高速道路 | 道路

出典　小学館　日本大百科全書(ニッポニカ)日本大百科全書(ニッポニカ)について　情報 | 凡例

<<: Valley head erosion

>>: Black pottery