When there are **puddles of water on the road**, it is important to **reduce speed** for several reasons:

- **Aquaplaning:** This phenomenon occurs when the tires cannot displace all the water from the road, causing the vehicle to lose traction and skid. This is more likely at **high speeds** and with worn or wide tires. Reducing speed helps prevent aquaplaning.

- **Visibility and grip:** Heavy rain can impair visibility and reduce the tires' grip on the pavement, increasing the braking distance. Driving more slowly allows for better reaction to these conditions.

- **General precautions:** When driving in the rain, it is advisable to keep the tires in good condition, check the windshield wipers, and brake gently. Additionally, it is crucial to check the brakes' functionality after passing through a puddle.

In summary, **reducing speed** when encountering puddles is an essential safety measure to avoid losing control of the vehicle and ensure safe driving.