Directions: please complete the following passage by filling in the blanks with exactly what you’ve heard. As city populations worldwide continue to grow, more people are driving than ever before. Urban planners are looking for 1 to the problem. Some believe the answer is to make streets wider and highways bigger . However, studies show that when streets become wider, all that happens is that mor e cars come onto the roads, 2 the problem. Other studies confirm that traffic is 3 caused by too few roads or by streets that are too narrow. Researchers have found that the main cause of many traffic jams is human decision-making. Thousands of cars on the same road means thousands of 4 drivers making different choices: How fast should I go? Which street should I drive on? How far should I stay from the car in front of me? With this in mind, urban planners —— and car makers —— ar e now exploring another 5 in order to reduce traffic: driverless cars.