Urban environments are becoming increasingly congested (overcrowded, especially with traffic or people), placing enormous pressure on city infrastructure (the basic systems a city needs, such as roads, water, and transport). Many governments have attempted to alleviate (to reduce or lessen a problem) this pressure through investment in public transport. However, critics argue that such measures are merely superficial (dealing only with the surface, not the real cause) unless accompanied by deeper structural (relating to the fundamental organisation of a system) reform of how cities are planned and built.