**High beam headlights** or **main beam headlights** are designed to improve visibility on roads outside urban areas, especially when there is little natural light. However, their use is **prohibited in certain situations** to avoid dazzling other drivers.

- **Within towns and cities**, high beam headlights should not be used. This is because urban areas are usually well-lit, and the use of these lights could dazzle other drivers and pedestrians.

- It is also prohibited to use them when the vehicle is stationary, as it is not necessary to illuminate the road in these circumstances.

- It is important to avoid dazzling, so if it is necessary to warn other drivers of a danger, the lights should be flashed intermittently.

Therefore, the correct answer is that it is prohibited to drive with the high beam on **where there is a risk of dazzling and on urban roads**.