their franchised bus system and road infrastructure in comprehensive alignment with their rail services. China's large cities such as Beijing, Shanghai, and Guangzhou recognize rail transit lines as the framework and bus lines as the main body to their metropolitan transportation systems. The Japanese Shinkansen was built to meet the growing traffic demand in the "heart of Japan's industry and economy" situated on the Tokyo-Kobe line. Wartime roles and air targets In the 1863-70 decade the heavy use of railways in the American Civil War, and in Germany's wars against Austria and France, provided a speed of movement unheard-of in the days of horses. During much of the 20th century, rail was a key element of war plans for rapid military mobilization, allowing for the quick and efficient transport of large numbers of reservists to their mustering-points, and infantry soldiers to the front lines. The Western Front in France during World War I required many trainloads of munitions a day. Rail yards and bridges in Germany and occupied France were major targets of Allied air power in World War II. Positive impacts Railways channel growth towards dense city agglomerations and along their arteries, as opposed to highway expansion, indicative of the U.S. transportation policy, which encourages development of suburbs at the periphery, contributing to increased vehicle miles travelled, carbon emissions, development of greenfield spaces, and depletion of natural reserves. These arrangements revalue city spaces, local taxes, housing values, and promotion of mixed use development. Negative impacts Bryant Chad found that in 1840s Austria the arrival of railways and steam locomotives angered locals because of the noise, smell, and pollution caused by the trains and the damage to homes and the surrounding land caused by the engine's soot and fiery embers; and since most travel was very local ordinary people seldom used the new line. Pollution A 2018 study found that the opening of the Beijing Metro caused a reduction in "most of the air pollutants concentrations (PM2.5, PM10, SO2, NO2, and CO) but had little effect on ozone pollution." Modern rail as economic development indicator European development economists have argued that the existence of modern rail infrastructure is a significant indicator of a country's economic advancement: this perspective is illustrated notably through the Basic Rail Transportation Infrastructure Index (known as BRTI Index). Subsidies Asia China In 2014, total rail spending by China was $130 billion and is likely to remain