It’s summer. In the United States, it’s the season of swimming pools, barbeques (户外烤肉), camping and road trips. 　　Road trip vacations where the car journey is part of the fun are especially popular with college students, who like to explore the country on wheels. These budget trips are ideal for students who often have plenty of free time but little money. 　　Driving trips first became popular in the 1920s. Newly paved roads and improved cars made it possible to travel longer distances. Motels (汽车旅馆)started appearing outside cities. 　　By the 1950s, car ownership became the norm. Construction of the US interstate (州际的) highway system began in 1956 and motel and restaurant chains popped up (突然出现) everywhere making long distance trips easier. 　　Today, the US has the highest car ownership rate in the world. Only 8 percent of American homes have no car, according to the most recent US census. Though many college students don’t own a car, most have access to one. 　　Hawkins’ most memorable road trip took place over spring break. He and two friends drove from New York to New Orleans to volunteer, helping rebuild the city after Hurricane (风暴) Katrina hit it last July. They crossed the country in two days and slept in their car in church parking lots. 　　Roberts’ road trip to Canada last winter was even more eventful. Upon arriving in Montreal, they were lost in a blizzard and shivering in the -25° cold. To find their hotel, they turned on a laptop (笔记本电脑) and drove around in circles until they found a spot with wireless Internet coverage. 　　“I know we should have planned better, but we’re young. Now, when I see those guys I always say: ‘Remember when we were lost in the snow storm!’ I’ll never forget that.”