The development of Siberia was hampered by poor transportation links within the region as well as between Siberia and the rest of the country. Aside from the Sibirsky trakt, good roads suitable for wheeled transport were few and far apart. For about five months of the year, rivers were the main means of transportation; during the cold half of the year, cargo and passengers travelled by horse-drawn sleds over the winter roads, many of which were the same rivers, now ice-covered.