HONG KONG — The Hong Kong-Zhuhai-Macao Bridge moved a step closer to completion Wednesday morning, with closure of the main structure into a single link.

The Hong Kong-Zhuhai-Macao Bridge Authority said the principal span, and the island and tunnel sections, have been completed to 4,700 meters, or 80 percent of the planned length, ultimately to connect Hong Kong to the Pearl River Delta.

The closure of the link means a full scale effort can get under way to roll out the bridge deck pavement and begin work on traffic engineering.

This undated photo shows the main structure of the Hong Kong-Zhuhai-Macao Bridge. (Courtesy of Hong Kong-Zhuhai-Macao Bridge Authority)

The 55-kilometer-long link comprises three parts – the offshore bridge and tunnel; the Boundary Crossing facilities at Hong Kong, Zhuhai and Macao; and the linking routes connecting the three cities. The main structure of the bridge comprising a 6.7-km underwater tunnel and a bridge span of 22.9 km. Artificial islands will be built at both ends of the tunnel.

The bridge, first planned in 1983, is expected to be completed by the end of next year at the earliest. Once when the bridge completed, commuting times between Hong Kong and Zhuhai will be considerately reduced from three and half hours to only half an hour.

The completion of Hong Kong section of the bridge, built independently by Hong Kong SAR government, was postponed for a year in September, 2015, after it was reported that the artificial islands had migrated between six and seven meters.

This undated photo shows the Hong Kong-Zhuhai-Macao Bridge. (Courtesy of Hong Kong-Zhuhai-Macao Bridge Authority)