Berlin, and 28 out of 29 consulates, were situated here. The first traffic light tower in Germany was erected at Potsdamer Platz on 20 October 1924 and went into service on 15. December 1924 in an attempt to control the sheer volume of traffic passing through. This traffic had grown to extraordinary levels. Even in 1900, more than 100,000 people, 20,000 cars, horse-drawn vehicles and handcarts, plus many thousands of bicycles, passed through the platz daily. By the 1920s the number of cars had soared to 60,000. The trams added greatly to this. The first four lines had appeared in 1880, rising to 13 by 1897, all horse-drawn, but after electrification between 1898 and 1902 the number of lines had soared to 35 by 1908 and ultimately reached 40, carrying between them 600 trams every hour, day and night. Services were run by a large number of companies. After 1918 most of the tram companies joined. In 1923, at the peak of the Hyperinflation the tram traffic was stopped for two days and a new communal company called Berliner Straßenbahn-Betriebs-GmbH was founded. Finally in 1929 all communal traffic companies (Underground, Tram and Buses) were unified into the Berliner Verkehrsbetriebe (Berlin Transport Services) company. At the Potsdamer Platz up to 11 policemen at a time had tried to control all this traffic but with varying success. The delays in tram traffic increased and the job was very dangerous for the policemen. The Berliner Straßenbahn-Betriebs-GmbH started researches to control the traffic on the main streets and places in 1924. Berlin traffic experts visited colleagues in Paris, London and New York. They had to organize the traffic, define traffic rules and select a solution to control the traffic. In New York, Fifth Avenue they found traffic light towers designed by Joseph H. Freedlander in 1922 which can be regarded as a model for the Berlin tower. The Potsdamer Platz five-sided 8.5 m high traffic tower was designed by Jean Kramer, a German architect. The traffic lights were delivered by Siemens & Halske and mounted on top of the tower cabin. A solitary policeman sat in a small cabin at the top of the tower and switched the lights around manually, until they were automated in 1926. Yet some officers still remained on the ground in case people did not pay any attention to the lights. The tower remained until October 1937, when it