Have you ever noticed how busy our roads are becoming? Every year more and more cars are using them. Already in such countries as America, almost every family has a car. Many accidents happen because cars are now made to travel very fast. Also, people waste time and money every day as long lines of cars move slowly into towns and cities. In most big towns it is very hard to find parking spaces. Wide, smooth  , straight   roads must be built now in place of the old and narrow roads. These roads must not pass through towns and cities. They must not be crossed by other roads. Today such roads are being built  in many countries in the world. These roads have at least two lanes , one for slow-moving traffic and the other for fast-moving traffic. These roads do not pass through town and cities; horses and bikes are not allowed on them. Accidents do not usually happen. Cars can travel hundreds of miles without having to stop. But these modem roads often cannot be built in towns and cities. Before a road in a town can be made wider, many buildings have to be pulled down. Some people feel that more car-parks should be built outside a city, then the drivers should leave their cars and catch a bus or take a taxi to their offices. It is hard to build new roads in towns because  _  .
horses and bikes go there there are too many cars there are too many people many buildings have to be pulled down