inaugurated the
Autostrada dei Laghi ("Lakes Motorway"; now parts of the
Autostrada A8 and
Autostrada A9), the first
motorway built in the world, In the following decades the State invested significantly in the construction of roads, particularly in the South, but these roads were progressively delegated to the provinces, paradoxically causing a reduction in the extension of the national road network in the face of a strong increase in
provincial roads. Furthermore, the road network was considered complementary to the
railway network, on which long-distance traffic travelled, to the point that for a long time there was a ban on classifying roads on routes already served by the railway as national. The extension of the road network made it necessary in 1911 to update the list drawn up almost 30 years earlier, formalized with Royal Decree no. 221 which now included 84 national roads. The advent of the automobile, which required the availability of fast and well-paved roads, changed the situation, and in the immediate post-war period it was decided to revisit the issue. The royal decree n. 2506 (published in the
Gazzetta Ufficiale of 4 December 1923 no. 284) classified the roads into 5 classes. However, the 1923 reform did not resolve the issue about road management, and was, in the end, not implemented. The growing centralization of power of the
fascist regime however led to the definitive affirmation of the centralist management model, which culminated in 1928 with the creation of the Azienda Autonoma Statale della Strada (AASS) (law 17 May 1928, n. 1094, Official Gazette n. 127 of 05/31/1928); which would later become
ANAS in 1946. Italy was the first country in the world to build a motorway, defined as a road reserved for fast traffic and motor vehicles only. The most motorized
Italian regions were those of
northern Italy and
central Italy, with
Lombardy at the top of the list with over 38,700 cars in 1923, while at the bottom of the list was
Basilicata with 502 cars. In 1939, a year before Italy entered into the
World War II, the construction of the Genoa-
Savona motorway (the current
Autostrada A10) was approved. The first official regulatory definition of a motorway dates back only to 1933 with Royal Decree no. 1740 of 1933 which defined a motorway as a road reserved for motor vehicles only. The legislative decree 17 April 1948, n. 547 then defined motorways "as those communication routes reserved for paid transit of motor vehicles, built and operated by the A.N.A.S. or by private individuals, with or without State contributions". In 1955 the
Romita law was promulgated by the Senate and the Chamber of Deputies and it contemplated that the motorway network must be present in all regions. Also in 1955, work began on the Genoa-Savona and the doubling of other single carriageway motorways thanks to the financing law no. 1328/1955. The law of 7 February 1961, n. 59 defined motorways "as those communication routes exclusively reserved for the selected transit, usually for a fee, of motor vehicles and motorbikes, without level crossings or in any case unattended, which are recognized as such by decree of the Minister for Public Works". at km 1,000 on the state highway number 16 Starting from the mid-1960s, ANAS also began to build a network of
dual carriageways which often flanked or completed the routes of the state highways, but did not formally replace them. These roads, initially called in the most disparate ways, were subsequently cataloged under the name of new road ANAS (NSA), also followed by a progressive number. The law of 12 February 1958, n. 126 as amended by law no. 167 of 9 April 1971, classified roads as state (main communication and ordinary), provincial, municipal, local and military. In 1961, by Law 24 July 1961 n. 729, the construction of the Adriatica (
Autostrada A14), Naples-Canosa (
Autostrada A16) and Caserta-Salerno (
Autostrada A30) motorways was approved. The same law provided for the construction of motorway junctions. Also in the 1960s, the first automatic pay stations were introduced for paying tolls only with coins. In 1964, the
Autostrada A1 Milan-
Rome was completed, the first dual carriageway motorway in the world with sections also in the mountains. In 1973 the first motorway in
Sicily (the
Autostrada A18) was inaugurated. In the 1970s the
Grande Raccordo Anulare was classified as a motorway. In 1975, law 492 was promulgated (in force until the 1990s) which provides for the blocking of motorway construction due to the
oil crisis. Until 1992 with the previous Italian traffic code the technical standards in force were those of the CNR 78/80 standard of the C.N.R. Official Bulletin. n. 78 of 28 July 1980. In 2001, as a consequence of the autonomist reforms of the late 1990s, many state highways were handed over to the
regions, and from them to the
provinces; the State kept for itself only a skeleton of fundamental roads, as well as those leading to the main border posts with other States. From a classification point of view, this has led to an extreme and confusing variety of new acronyms and street numbers, carried out independently by each local authority without a common criterion; consequently, in common usage the roads have often continued to be identified as "former state highway number...". on 23 July 2014 In 1997 work began on the modernization of the
Salerno-
Reggio Calabria motorway. Completed in 2017, it was then renamed
Autostrada A2, to replace the old name which then remained only for the Naples-
Salerno section. In 2001, with the doubling of the
Autostrada A6, all motorways in Italy are dual carriageways. In 2009 the
Mestre bypass was opened (classified as Autostrada A4). Between 2014 and 2015, the
Autostrada A35,
Autostrada A36,
Autostrada A58,
Autostrada A59, and
Autostrada A60 motorways were opened. In March 2022, the 3-lane section of the Autostrada A1 southbound between
Barberino di Mugello and
Calenzano was opened, which - although not officially - constitutes the natural continuation of the
Variante di Valico; in this stretch the Santa Lucia tunnel is crossed which, at , is the longest 3-lane tunnel in Europe. Since 2018, faced with the difficulty of many local authorities in guaranteeing the maintenance of former state highways, a "road return" project was launched which involves the return of almost 7,000 km of roads to ANAS, staggered in two phases. Consequently, these roads have once again assumed the pre-existing state highway numbering already removed in 2001. ==Technical classification==