Answer:
Advances in assembly line mass production
Large-scale production reduces costs of automobiles
Growth in personal automobile ownership
Commuters face traffic congestion
Step-by-step explanation:
After the First World War, the car became one of the main transport vehicles. Thanks to the introduction of conveyor production, car models available to people with average incomes occurred.
A revolution in the American automotive industry was made by T model of Henry Ford, who used the American standardization system on his conveyors. Thus the era of continuous production began. In 1908, Ford launched the Model T with a 20 horsepower engine. The demand for this model was so great that already in 1912 a new plant was built for its assembly in Michigan, exemplary for its time.
The conveyor method gave a giant acceleration to the production of cars - 1000 per day or more, and also led to a reduction in the production costs.
An individual car has become a more massive means of transportation than public transport. The car, in turn, caused a revolution in the road business, influenced urban planning principles, stimulated the growth of the metallurgical, glass, rubber, paint and varnish and oil industries, and a car service industry arose.