Be careful because the manhole cover is slippery on rainy days!

Since Yokohama City had an international trading port, in 1869, as a sanitary measure for foreign settlements, we started improving sewerage systems earlier than other cities. After that, the maintenance was delayed due to the Great Kanto Earthquake and World War II, etc., but from 1957, full-scale sewerage development with a terminal treatment plant was started, and the current sewerage penetration rate is about 100% .

The sewer that has been maintained in this way has built a huge network in underground spaces such as roads, but I think that only manholes on the road can be seen directly by citizens.

In addition, manhole of sewer is installed to perform maintenance such as pipe inspection or cleaning work, and the number is about 540,000 in the city alone.

By the way, due to changes in road conditions in recent years, such as an increase in large vehicles, manhole covers have been adopted nationwide in order to prevent vibration and noise caused by vehicle traffic. .

Yokohama City has more hills than other cities, so the roads have relatively high steep slopes. For this reason, as a countermeasure against slippage, the manhole cover has a pattern on the surface, but please be careful as it may slip depending on the type of shoe sole, such as on a rainy day.

In addition, in order to respond to pedestrian measures and barrier-free for the aging society in the future, we will consider measures to prevent slips to the manhole cover on steep slopes.