Why do streetcars use 600 volts DC?

Streetcars use 600 volts DC primarily because it is a standard voltage that offers a good balance between efficiency and safety for urban transit systems. This voltage level reduces energy loss over the distribution lines and allows for the use of smaller, lighter wiring compared to higher voltages. Additionally, DC systems are simpler and more reliable in terms of control and operation, making them well-suited for the frequent stops and starts typical in streetcar service. Moreover, many existing infrastructure and vehicles have been designed around this standard, facilitating maintenance and interoperability.