What should you do if you encounter a car that has its turn signal on but has not turned?

When you encounter a car with its turn signal on but not turning, proceeding with caution is the most prudent approach. This action allows you to assess the situation without making any hasty decisions that could lead to potential hazards. Drivers might activate their turn signals for various reasons, such as deciding to change lanes or waiting to determine whether it's safe to turn. By maintaining a cautious distance and being prepared for any sudden movements, you ensure your safety and that of others on the road.

Choosing to speed past the car could lead to a dangerous situation if the driver suddenly decides to change lanes or turn. Assuming the driver is confused might lead to a lack of appropriate action, as it undermines the need for vigilance. Blowing your horn might alert the driver, but it could also startle them and cause unintended consequences. Thus, the safest and most responsible choice is to proceed with caution, preparing for any unexpected changes in the driver's behavior.