Chiang Mai is also becoming a regional hub for transportation, aviation, education and medical services. Yet it is rapidly outgrowing its infrastructure. The once-compact city centre is giving way to sprawling expansion. Unplanned urban development, the absence of traffic management policies and practices, and a lack of integrated transport and land use planning have left Chiang Mai with major transport issues. Traffic congestion, air pollution, an inadequate Public transport system and insufficient pedestrian walkways further encourage the use of private cars and motorbikes. As a result, personal mobility, live ability and environmental sustainability have declined, and urban transport has become a major source of greenhouse gas emissions. Yet maintaining a clean and uncongested environment is integral to the tourist experience that Chiang Mai is marketing to both domestic and foreign tourists. This issue became an important impetus for the city to look further into options to reduce greenhouse gas emissions.