Which of the following is typically indicated by manual road signs?

Manual road signs are primarily used to communicate important information to drivers, particularly in contexts like road work situations. During construction or maintenance activities, manual road signs are often employed by traffic management personnel to direct traffic, provide detours, or alert drivers to changes in road conditions. This is essential to ensure safety for both drivers and workers, as conditions on the road can change rapidly during these times.

In contrast, traffic signal changes are typically indicated by electronic traffic signals rather than manual signs. Weather conditions affecting driving are generally communicated through other means, such as electronic message boards or radio updates, rather than manual signs. Vehicle registration requirements are usually not indicated on road signs at all; they are more related to administrative processes handled by vehicle registration authorities. Therefore, option B stands out as the correct answer, aligning precisely with the primary function of manual road signs in managing traffic during road work situations.