What must a vehicle do at a traffic intersection if the signal is not clear?

At a traffic intersection where the signal is not clear, the appropriate action for a vehicle is to stop and assess the situation. This ensures that the driver can evaluate potential risks, including the presence of other vehicles, pedestrians, or cyclists, and make an informed decision about how to proceed safely. Stopping provides an opportunity to look for any traffic signs, signals of other vehicles, or indications from law enforcement that may clarify the proper action to take.

Proceeding with caution might imply that one can move forward without fully stopping, which could lead to dangerous situations if misjudgments are made regarding the right-of-way or traffic conditions. Yielding the right-of-way assumes that other vehicles or pedestrians have the right to proceed, which cannot be effectively determined without first stopping and assessing. The option suggesting that all vehicles can proceed simultaneously contradicts traffic safety principles, as it could lead to collisions and confusion among drivers. Therefore, stopping to assess is the safest course of action in unclear traffic situations.