Steel became the predominant material for bridge construction during the latter half of the 1800s. The prerequisite was that high-quality steel could be produced in large quantities at low prices. At the same time, research on bridge construction was advancing. The goal was to reduce the amount of material and therefore the weight of the bridge, while also allowing for longer bridge spans. Now, it was possible to traverse widths that were previously impossible.

The first steel railway bridges were built in the 1860s. These were simple beam bridges with spans of up to 20 metres. In the quest to reduce weight and material, truss technology was eventually developed, which is still used today. Unlike a solid iron beam, the truss beam is reduced to a skeletal structure. The construction is very strong in relation to its weight.

An older example of a truss bridge is the Pytte Bridge in Ängelholm, built in 1904, shown here as a model. This type of construction was very common between 1870 and 1910. The Pytte Bridge consists of two truss beams with a roadway for traffic in between. The curved shape of the truss beams reveals where the construction is most exposed. The bridge needs to be strongest at the centre.

A later example of a truss bridge is parts of the Öresund Bridge, with spans of 140 metres between the concrete pillars. The components of the truss beams are hollow and consist of sheet metal with box sections, providing a strong, lightweight, and stable structure. The high bridge section of the Öresund Bridge is a so-called cable-stayed bridge. The bridge's four pylons support the roadway through a series of inclined cables. This construction is used today for the longest bridge spans.

The disadvantage of steel structures is corrosion. Therefore, since the 1800s, the material has been protected with paint or galvanization. Since the 1940s, bridge parts have been welded together instead of being riveted, reducing both weight and the risk of corrosion.