Transport for London has introduced a Low Emission Zone covering greater London an area larger than the congestion zone. A network of monitoring cameras will match freight vehicles to a database of EU emission compliant vehicles. It operates 24 hours a day, seven days a week. It also applies on weekends and public holidays. Other metropolitan areas are tracking the concept as a possible solution to urban air pollution.Heavily polluting lorries face charges of £200 per day to enter the LEZ.