HONG KONG — The streets around Centre Street, in the Hong Kong neighborhood of Sai Ying Pun, are a microcosm of the vibrant, small-business life that makes this city as colorful as it is. There are shops selling large, wobbling blocks of fresh tofu, bean sprouts and papayas. There are tiny stalls selling fish balls, pork, noodles or copy books to local schoolchildren. There are hardware stores, cheap clothing outlets and clattering car repair shops, whose shrines to the Chinese Earth God provide a colorful counterpoint to the oil-stained floors inside.

Much of this life, however, is in the process of disappearing, as a new architectural addition to Centre Street — an outdoor escalator that grinds up the street’s steep incline under a modernist roof — takes its toll on the neighborhood’s commercial ecosystem.

Hong Kong is an exceedingly hilly city. The high-rises that house its residents and the offices that have turned the former British colony into an international financial hub are wedged between the sea and steep peaks. In days of yore, wealthy residents had themselves carried in sedan chairs when they wanted to travel to the higher reaches of the city. In 1888, a tram began trundling up and down the steep incline to Victoria Peak.

More recently, urban planners hit upon the concept of outdoor escalators to make uphill districts more accessible, especially during the hot and humid months. A little over two decades ago, an escalator that winds uphill in about 20 segments and has become a tourist attraction in its own right began operations in an area now known as Soho.