Silk road from 200 bce to 400 ce?

This was a trade route 6400 km long(4,000 miles) that connected china with the mediterranean,it was in most use in antiquity, when silk was taken westwards,and wool and precious metals were taken eastwards. Merchants travelled along the silk route for hundreds of years but it became less important by about 1000 ad, the cities along the route had become bigger and could control the trade that came through,they also demanded a portion of the merchants goods before they would allow them through, so the cities along the route became rich. but it was again travelled in the middle ages,notably by marco polo.Although it was superseded by sea routes in the 15th century it has remained important for communications in south east asia. An oil pipeline some 3017km long(1875miles) is currently (2005) being constructed along the silk road from china to kazakhstan, it may be finished by now!