Travel is used to mean the general activity of moving from one place to another. Journey refers to traveling a long distance, or traveling regularly, emphasizing on the idea of traveling itself. Trip refers to traveling a short distance, or an unusual journey, emphasizing on the place or the reason of traveling.
Air travel is faster than rail travel. His job involves a lot of traveling.
We had a long journey through the mountains. He usually reads the paper during the train journey to work.
His job involves a lot of business trips. Our trip to Las Vegas was great.