What is the purpose of cross braces in scaffolding systems?

Cross braces in scaffolding systems serve a crucial function by enhancing the stability and support of the scaffolding frames. When they're installed diagonally between vertical members, they effectively create a triangulated support structure, which helps distribute loads more evenly and prevents the scaffolding from swaying or collapsing. This added stability is essential, especially when scaffolding is used at height or under varying loads, as it ensures the safety of the workers and equipment involved.

Other functions hinted at by the other options are not the primary purpose of cross braces. For example, while scaffolding planks are indeed supported by the framework, it is not the role of cross braces to provide this support directly. Additionally, although safety zones are important on construction sites, marking these areas isn't the function of cross braces.