Read the passage below and answer the question that follows. 'Traffic congestion in Lagos has become a daily ordeal for millions of residents. The first cause is simple arithmetic: the number of vehicles has grown far faster than the length of usable road. Second, many of the roads that do exist are in poor condition, so that a single pothole on a bridge approach can slow thousands of cars. Third, the indiscipline of drivers, who drive against traffic, stop anywhere to pick up passengers and ignore traffic lights, multiplies the effect of every minor obstruction. A fourth cause is the concentration of offices, banks and markets on the Island, which forces the working population to move in the same direction at the same hours. Finally, the absence of a reliable mass transit system leaves most people with no alternative to the private car or the danfo bus. The consequences are severe: hours lost in traffic every week, higher fuel costs, stress-related illness and reduced productivity.' In five sentences, one for each, summarise the causes of traffic congestion in Lagos as given in the passage. (20 marks)