【明報專訊】A three-day trial run was carried out a few days ago at the Hong Kong-Zhuhai-Macao Bridge (HZMB) in preparation for the bridge's opening expected at the end of this year. The HZMB, the longest bridge-cum-tunnel sea crossing in the world, has been fully put to the test by Super Typhoons Hato and Mangkhut over the past two years. The fact that it has stood the tests should dispel worries about the bridge's safety. Hong Kong, Macao and the mainland have separate ways of getting things done. The principle adopted in designing the HZMB, "adhering to the highest rather than the lowest standards", can be used as a good guide for future cooperation in the Guangdong-Hong Kong-Macao Greater Bay Area (the Greater Bay Area). In this respect, Hong Kong can play a more active role while learning from others' strengths. Because of the dropping volume of Hong Kong's cross-boundary land freight transport as well as the upcoming opening of other crossings linking the east and west of Pearl River Delta like the Shenzhen-Zhongshan Bridge and the Humen Second Bridge, the HZMB is already facing significant challenges and competition even before it comes into operation. The key of securing traffic and passenger flow for the HZMB will lie in whether Hong Kong can play its part well and fight hard to attain the leading position in the integration of the Greater Bay Area.