Tranebergsbron (Swedish: "The Traneberg Bridge") is a double arch bridge in central Stockholm, Sweden. Stretching over the strait Tranebergssund it connects the major island Kungsholmen to the western suburb Bromma. It has a road and also metro tracks.
Part of the ambition of King Gustav III (1746–1792) to construct a road from the city to the palace at Drottningholm Palace, the first bridge at this location was a floating bridge finished in 1787, defrayed by the funds granted the king as christening gift while namned crown prince in 1779. As neglected maintenance made it necessary to rebuild the bridge by the 1850s, the new floating bridge was then relocated slightly southwards, thus reaching into the valley on the western shore.
As population in the western suburbs grew in the early 20th century, the necessity of a bridge allowing cars, trucks, and trams became increasingly apparent, and 1911-1914 a pontoon bridge was built in parallel to the old bridge. With its concrete abutments, and steel rafts and superstructure, the bridge was 227 metres in length, 6,3 metres wide, and had a 37 metres long swing span to allow the passage of ships. Soon insufficient, it was widened to 8,5 metres in 1921-22, and at the same time the old floating bridge closed for traffic.
The western suburbs continued to prosper however, and soon after a decision in the City Council in 1931 work begun on a double concrete arch bridge - for a year the largest in the world - some 100 metres north of the existent bridge. When inaugurated in 1934, the bridge was 580 metres long and 27,4 metres wide, with beam viaducts, with spans of 13 metres, flanking the main 181 metres wide double arch on both sides. A vertical clearance of 26 metres was chosen because of a planned sea port north of the bridge. The bridge was divided into one section for road traffic and one for the tramway. In the early 1950s the tramway was converted to metro railway.
The design work for the 1934 bridge was credited to Swedish architect Paul Hedqvist.
By the end of the 20th century, the roadway was in such bad state the bridge had to be shut off for heavy vehicles during a long period. After a new third arch bridge had been added south of the old and inaugurated in 2002, the two original bridges were in practice rebuilt and the entire structure officially inaugurated by Crown Princess Victoria August 31, 2005.