Travel sickness is caused by a disturbance in the inner ear as a result of repeated motion. The symptoms include nausea, vomiting, sweating and dizziness. If you are traveling in the dark either at night or during heavy fog or rain where your vision is obscured you will be susceptible to motion sickness. These are some precautions you can take to avoid suffering from it.
If you are not driving and it is dark outside keep your eyes closed to prevent conflict between the eyes and the inner ear.
Do not sit backwards from your direction of travel.
Avoid eating heavy meals and avoid spicy, fatty foods before and during travel. Do not start a trip on an empty stomach, have a light starchy meal to settle the stomach and snack regularly while traveling.
Avoid alcohol the night before you are to travel.
Minimize movement while traveling, this means driving slowly, sitting in the middle of the plane over the wing. When in a car sit in the front seat and look straight ahead and get plenty of fresh air.
Avoid reading while traveling as there is a conflict between what the body feels and what you read.