Final answer:
At highway speeds, it's recommended to look ahead 1/4 mile to allow for adequate reaction time to road conditions and potential hazards.
Step-by-step explanation:
The distance you should look ahead while driving at highway speeds is generally 1/4 mile. This is because at high speeds, you need more time to react to unexpected events or hazards on the road. When driving at a speed of 100 km/h, which is approximately 62 miles per hour (mph), a good rule of thumb is to maintain a visual lead time of about 12 to 15 seconds ahead of your vehicle. Given that a car traveling at highway speeds covers significant distance in a short period, scanning further ahead allows for safe maneuvering and stopping if necessary.
Considering scenarios such as drag racing, the distance of one quarter of a mile is covered in a very short time, demonstrating how quickly situations can evolve on the road and highlighting the importance of looking far enough ahead.