Central Kowloon Bypass Yau Ma Tei section: rebar suspected not screwed into couplers; Highways Department says alternative design adopted

A video circulating online of construction of the Central Kowloon Bypass (Yau Ma Tei section) tunnel in 2024 shows multiple lengths of rebar suspected not having been screwed into couplers. The Highways Department replied to enquiries saying the contractor assessed at the time that construction was difficult and proposed an "alternative design", drilling holes at suitable locations to insert additional rebar, which was approved in advance. The Highways Department did not specify which locations used the alternative design, nor did it explain in detail how structural safety is ensured when rebar is not screwed in. The section opened to traffic at the end of last year.