and Berliners from both sides of the former divide, has not really materialised. There are criticisms that the development does not sit easily with or connect with its surroundings, and as a result Berliners have had difficulty accepting it as theirs (despite the fact that the choice of Hilmer & Sattler's masterplan was partly because it was the only one to address the way the development juxtaposed with the Cultural Forum immediately to the west, although the Cultural Forum has itself faced similar criticisms of its own). Another, more psychological factor that has played a part here is that a long-standing mutual distrust or antipathy felt between former East Berliners and West Berliners (Ossis and Wessis according to the well-known slang terms), is still very much in evidence in the city and elsewhere in Germany, and bold civil engineering projects and architectural statements are not going to make it go away by themselves. Politicians past and present have been accused of short-sightedness in speculating that they would. It was feared that the economic downturn might exacerbate all these problems. On the whole, however, Potsdamer Platz seems to have weathered the storm. Meanwhile, Deutsche Bahn AG were due to relocate to a purpose-built new structure at Berlin's new main train station (Berlin Hauptbahnhof), when the lease on the Sony Center's Bahn Tower expired in 2010. However, in April 2008 Deutsche Bahn announced that they were seeking to extend the lease on the Bahn Tower by another three years. This deal was finalised in late 2009. Since then the lease has been extended to 15 years. Transport Before World War II, Potsdamer Platz had much streetcar traffic. The last remnants were removed in 1991. Unlike, for example, Friedrichstrasse station, Potsdamer Platz is not a really important intersection point for the U and S-Bahn system. However, due to its location on the north–south route to the main station, parallel to the aboveground buildings, it was also connected to the regional traffic with a tunnel station. Regional trains of the DB and the ODEG, the S-Bahn (north–south tunnel) and the U2 underground line currently stop at Potsdamer Platz regional train station. Via numerous bus lines, the course can also be reached. In the medium term, a tram connection through the Leipziger Strasse is planned, which can be supplemented or even replaced by the long-planned U3 underground line. In the north–south direction, another S-Bahn line