Between 5pm and 6pm, it is hard to believe that Lowu is a border crossing. The lines at immigration are packed by schoolchildren going home to Shenzhen, and the place has a carnival atmosphere.
People shout rendezvous information across the desks to each other before they traipse across the bridge spanning the Shenzhen River. Children jostle for a place, and minders struggle to keep them under control. Immigration officers try to take seriously the formalities of swiping ID cards. It's all great fun.
It can be similarly entertaining to cross from Macau to Zhuhai at certain times of the day. The enormous clearance hall at Gongbei, with 27 lanes, seems to be populated almost entirely by elderly people dragging carts, each loaded with a single box. One could contain 12 cans of Pringles crisps. Or it could be shuttlecocks. Small-scale arbitrage between two economic systems is quite a sight.
Suit-clad business types are in the minority at these two points, but they hold the spotlight at the ferry and train terminals. There, they drag their trolley bags around in a rush, coffee in hand, tutting when immigration officials fail to process requests as quickly as their personal assistants do.
About 8,000 take the Kowloon-Guangzhou through train every day, slightly more than travel in the Pearl River Delta by boat. That's a fraction of the roughly 250,000 that go through Lowu, but significant nevertheless.
Seeing how everyday life proceeds across boundaries provides insight into human character anywhere in the world. In and around the Pearl River Delta, it is particularly educational. Nowhere else can you find such volumes of people moving from an information-rich, free-thinking, free-market society to a society where 'free' is a four-letter word and information is a tool of the governing class.
It is impossible not to believe that this flow is having a major impact on the less free of the two. Mainland customs officials might confiscate copies of Apple Daily at the border, but they cannot step into people's minds and erase their knowledge of what is going on in Hong Kong.