Since the US returned control of the Ryukyu Islands to Japan in 1972, development on Iriomote continued with finances from the Okinawan mainland. In 1977, a prefectural road was built that circles half of the island, which has led to a few Iriomote cat deaths every year due to traffic accidents. The Ministry of the Environment as well as the governments of Okinawa and Taketomi Town began installing road signs to warn people of Iriomote cats crossing the road, tunnels beneath the road for their safe crossing, zebra zones which create loud noises when cars ride over them, wide ditches on the sides of roads, and ditches on the side of the road that are inclined on one side in order to improve the preservation of the cats. However, many residents have objected to restrictions on land cultivation and improvement brought about by the measures in place to protect the Iriomote cat and other species on the island.