Until the end of World War I, largely under the influence of the Austro-Hungarian General Staff, transportation policy tended to establish a centralized road and railroad system focused on Budapest. The main railroad lines built before 1918 still represent the backbone of the Hungarian railroad system. Under the Trianon Treaty, Hungary lost about 60 per cent of its railroads and hard-surfaced roads, almost two-thirds of its navigable waterways and its Adriatic port, Fiume.
Efforts to integrate and modernize this truncated network were rather spasmodic. A considerable influence came from the landlords, whose search for markets led them toward Austria and Germany. Consequently, Trianon Hungary developed a communication system with the important veins leading westward. Inter-communication both for railroads and highways lagged. Only in the late 1930's was the construction of better highways begun, with an appropriation of 80 million pengo under a five-year plan for road building. By 1942, Hungary had succeeded in connecting a large number of previously isolated communities to the main road system. However, the railroad lines were comparatively neglected. Lack of capital and the worldwide depression were important factors in this delay.
Prewar Hungary had 815 miles of navigable waterways, including the Danube and its tributaries and the long sliver of Lake Balaton in Transdanubia. After the Danube, the two most important waterways were the Tisza and Koros rivers, which flow through the wheat region of the Great Hungarian Plain. These, however, were navigable only part of the year, being subject to drought in summer and ice in winter. Most river traffic passed up and down the Danube, which before the war had thirteen ports. The most important port, Budapest, drew international traffic with its free facilities at Csepel. In general, the waterway potential had not been exploited.