Trams in Klagenfurt  The Klagenfurt Tram network operated in various forms between 1891 and 1963, which was when diesel buses took over, reflecting lower operating costs at a time of relatively low prices for oil based fuels. In 2005, in response to exceptional levels of particulates pollution in Klagenfurt the city authorities proposed a resumption of tram services. A feasibility study was commissioned, but concluded that the cost of the necessary investment would be prohibitive. By the 1880 the population of Klagenfurt had reached almost 20,000, which was enough to justify fresh public transport investment. Between 1883 and 1885 various companies put forward plans for a tram powered by horses, steam or even electricity. It was not till 15 May 1891, however, that the city awarded its first tram concession. The company set up by the Vienna entrepreneur Adolf Springer was contracted to operate a horse powered tram service, and an experimental operation was almost immediately put in place. The first tram line, using a one-meter gauge, connecting the main station, on the city's south side, with the "Holy Ghost Square" ("Heiligengeist Platz") in the city centre was completed on 30 June 1891, and services began on 5 July 1891. The service expanded to the point where it employed a large number of summer tramcars, three winter tramcars and, at busy times, up to 24 horses. Helped by low personnel costs, the operation was cost-effective and popular, especially during the summer months, in a city with an economy that by now was already heavily impacted by a large scale but highly seasonal level of tourist business. Passenger numbers peaked in 1910 at 386,766. 1910 was also the system's final year of horse traction. In 1910 Siemens, working under a contract agreed with the city the previous year, began work on an electric tram system which was to replace its horse-drawn precursor. The first electric tram service, which connected the main railway station with "Theatre Square" ("Theaterplatz") opened on 6 May 1911. Significant further expansion followed later in the same year. In 1935, which coincidentally was the year in which traffic in Klagenfurt switched to driving on the right side of the road, saw a new tram service connecting the Military Swimming School with the city's newly expanded opened on the Wörthersee. The total length of tram lines now comprised 10.2 km (slightly more than 6 miles). The open ended "summer tramcars" that had been taken over from the horse-drawn trams in 1911 were still in use, and they were held in great affection so that now a new batch was ordered for the new line, with only very minor technical modifications.