In what type of bridge designs are open expansion joints commonly found?

Answer: B — Short span bridges

Open expansion joints are typically found in short span bridges due to their design and function. These joints allow for the necessary movement of the bridge deck due to thermal expansion, contraction, and other forces associated with varying loads. Short span bridges are generally simpler in their structural configuration and may not require the same degree of movement accommodation as longer spans, making open joints a practical solution for these structures. The design of open expansion joints is particularly advantageous for short spans because they provide ease of maintenance and effective drainage of water and debris, which are critical for preserving the integrity of the bridge elements. In contrast, long span bridges often employ more complex joint systems to manage movement and forces, given the greater distances they cover and the resultant stresses involved. Thus, while various types of bridges may feature expansion joints, open expansion joints are predominantly associated with shorter spans for the reasons highlighted.