Three Egyptian intercity highways were temporarily closed on Tuesday morning due poor visibility resulting from fog, the General Traffic Authority said. The Cairo-Alexandria Road, Al-Alamein Road (which connects the former with the North Coast), and the Shubra-Banha freeway (northwest of Cairo) were shut down in the early morning. Shortly before noon, the authority announced that the roads had been reopened. However, it urged drivers to reduce their speed and use safety measures, including using their headlights, fog lights and hazard-warning lights, to improve visibility for themselves and vehicles behind them. Egypt's meteorologists have issued warnings about morning fog in many parts of the country throughout the week, saying that daytime mist will turn to fog sometime after midnight and through the early morning. Last week, four people were killed and 39 others injured in a multi-vehicle collision on the Cairo-Alexandria Desert Road as a result of early morning fog, Temperatures are expected to drop slightly on Wednesday and Thursday, with the capital Cairo and the Nile Delta expecting highs of 21-22 Celsius and lows of 12 degrees C. Egypt's north coasts are predicted to see highs of 21 C and lows of 10-13 C. The northern part of Upper Egypt will be the coldest, with lows dropping to 7 degrees Celsius.