In 1878 the only railway in Bulgaria was the Rustchuk-Varna line (137 m.), constructed by an English company in 1867. In Eastern Rumelia the line from Sarambey to Philippopolis and the Turkish frontier (122 m.), with a branch to Yamboli (66 m.), had been built by Baron Hirsch in 1873, and leased by the Turkish government to the Oriental Railways Company until 1958. It was taken over by the Bulgarian government in 1908 (see History, below). The construction of a railway from the Servian frontier at Tzaribrod to the Eastern Rumelian frontier at Vakarel was imposed on the principality by the Berlin Treaty, but political difficulties intervened, and the line, which touches Sofia, was not completed till 1888. In that year the Bulgarian government seized the short connecting line Belovo-Sarambey belonging to Turkey, and railway communication between Constantinople and the western capitals was established. Since that time great progress has been made in railway construction. In 1888, 240 m. of state railways were open to traffic; in 1899, 777 m.; in 1902, 880 m. Up to October 1908 all these lines were worked by the state, and, with the exception of the Belovo-Sarambey line (29 m.), which was worked under a convention with Turkey, were its property.
The completion of the important line Radomir-Sofia-Shumen (November 1899) opened up the rich agricultural district between the Balkans and the Danube and connected Varna with the capital. Branches to Samovit and Rustchuk establish connexion with the Rumanian railway system on the opposite side of the river. It was hoped, with the consent of the Turkish government, to extend the line Sofia-Radomir-Kiustendil to Uskub, and thus to secure a direct route to Salonica and the Aegean. Road communication is still in an unsatisfactory condition. Roads are divided into three classes: "state roads," or main highways, maintained by the government; "district roads" maintained by the district councils; and "inter-village roads" (mezhduselski shosseta), maintained by the communes. Repairs are effected by the corvée system with requisitions of material. There are no canals, and inland navigation is confined to the Danube. The Austrian Donaudampschiffahrtsgesellschaft and the Russian Gagarine steamship company compete for the river traffic; the grain trade is largely served by steamers belonging to Greek merchants.
The coasting trade on the Black Sea is carried on by a Bulgarian steamship company; the steamers of the Austrian Lloyd, and other foreign companies call at Varna, and occasionally at Burgas.
The development of postal and telegraphic communication has been rapid. In 1886, 1,468,494 letters were posted, in 1903, 29,063,043. Receipts of posts and telegraphs in 1886 were £40,975, in 1903 £134,942. In 1903 there were 3261 m. of telegraph lines and 531 m. of telephones.
The principal towns of Bulgaria are Sofia, the capital (Bulgarian Sredetz, a name now little used), pop. in January 1906, 82,187; Philippopolis, the capital of Eastern Rumelia (Bulg. Plovdiv), pop. 45,572; Varna, 37,155; Rustchuk (Bulg. Russé), 33,552; Sliven, 25,049; Shumla (Bulg. Shumen), 22,290; Plevna (Bulg. Pleven), 21,208; Stara-Zagora, 20,647; Tatar-Pazarjik, 17,549; Vidin, 16,168; Yamboli (Greek Hyampolis), 15,708; Dobritch (Turkish Hajiolu-Pazarjik), 15,369; Haskovo, 15,061; Vratza, 14,832; Stanimaka (Greek Stenimachos), 14,120; Razgrad, 13,783; Sistova (Bulg. Svishtov), 13,408; Burgas, 12,846; Kiustendil, 12,353; Trnovo, the ancient capital, 12,171. All these are described in separate articles.