The border lines are awfully drewn. The Roman empire had not fully expanded to the Danube and much of Asia Minor was still occupied by client states, while the Han Empire never incorporated the Tarim basin (the huge Western appendix) into their empire. And the date, 1 AD, is arbitrarily chosen.

This map, as others have noted, is inaccurate. By 1 A.D. Palestina was reduced and incorporated as a province ruled by Rome. The map also badly indicates the Eastern borders of the Roman empire. Meanwhile, it appears to over-state Chinese hegemony in Northern Korea, Northern Vietnam, and the far west of what is now China. Surely there must be some other more accurate public domain map?