Management of Yokohama City Public Control Points conservation

In Yokohama City, the "Yokohama City Public Reference Point" has been set up in the city under the advice and guidance of the Geographical Survey Institute and the Japan Surveying Association to supplement the national triangular point used as a reference point for surveying work. .
The survey results of the Yokohama City Public Control Point can be confirmed in the Road and Highway Bureau Road Survey Division and the "Road Ledger Reading System (Image: 33KB)" installed in each ward Public Works Office.
After the Great East Japan Earthquake, the survey results were published as "World Geodetic System (Goding Results 2011)".

Because Yokohama-shi public reference point is installed mainly on road, removal may be necessary at the time of construction with excavation on road.
Therefore, when performing construction with excavation on road for appropriate management of Yokohama-shi public control point, we perform construction with excavation on road.
Based on "Yokohama-shi public control point management conservation summary (February, 2024 revision) (PDF: 914KB), I would like discussion with City of Yokohama, Road and Highway Bureau road investigation section.
Please refer to the documents related to public control points for specific procedures.

Types of Yokohama City Public Control Points

Type (Structural diagram)	Details	Grade※	Installation location	Notation in Yokohama-shi public reference point network map (image: 42KB)	Sign	Remarks
Primary point (PDF: 143KB)	Only the national triangular point is known.	First-class reference point	Mainly the rooftop of buildings	◎		Eccentric point, direction mark (including ground mark)
Primary supplemental points (PDF: 95KB)	An open point with the primary point as a known point. It can be used as a primary point.	First-class reference point	On the road (in the manhole)	◉
Secondary point (PDF: 121KB)	The primary point and the primary point are used as known points and are installed in polygons.	Level 2 Reference Point	On the road	◻
Second Section (PDF: 290KB)	This is the middle point between the primary point and the secondary point.	Level 2 Reference Point	On the road	◯

※Classes according to the Yokohama City Road Ledger Work Regulations
※February 29, 2024 Public control point management conservation outline was revised and will take effect on April 1, 2024.