The Metro carries a smaller percentage of passengers than buses or trams, only 350 million per year, but it is a crucial part of the system. The yellow line opened in 1896, making it the first underground railway in Europe. This line runs in the Pest side, starting at Vorosmarty Square, a plaza at the center of the inner city. It travels only 3.75 km, and carrying a small number of passengers (only 16 seats are inside each of the cars). However, it is connected to surface transportation and the other Metro lines through a central station. The red line runs from eastern Pest to the inner city and under the river, ending at the Southern Railway Station. The blue line runes from the south-east of Pest, at Ferihegyi International Airport, along the Danube to the city boundary in the north. The red and blue cars were made in the former Soviet Union, so the cars and the stations resemble those of Russia, with fast efficient service and lots of noise. The Metro is slated for expansion, but this project may not get off the ground until funds are available--an uncertain future now that the city is no longer centrally planned by Communists.