European route E33

European route E 33 is a series of roads in Italy, part of the United Nations International E-road network. 
It runs from Parma to La Spezia, both in Italy.
It leaves Parma, where it links to E 35 and heads south-west, reaching its destination of La Spezia, where it further links to E 80, a transcontinental route. This is exactly the same route as the Italian A15.
In practice, the number E 33 does not appear on any road signs. Instead, its entire stretch is signposted as E 31, creating a duplication with the E 31 in Germany and the Netherlands. This goes back to the numbering set forth in the original European Agreement on Main International Traffic Arteries (AGR) of 1975, in which Parma - La Spezia was numbered E 31 and Rotterdam - Ludwigshafen was numbered E 33. These numbers were swapped upon the AGR's entry into force in 1985, apparently resulting from the fact that the Parma - La Spezia route is entirely situated east of the Rotterdam - Ludwigshafen route so that the former should under AGR principles have a number above the former. This numbering change, however, never made it onto Italian signs.