How To Install Road Security Mirror

How to install road security mirror

1. Application range of the installation of road security mirror

1. This is to stipulate the general terms on the making and installation of the road security mirror which is necessary where adequate visibility is not secured under the road’s normal driving speed.

2. Installation must be performed according to installation blueprint and the instruction of the engineer.

3. Type of the road security mirrors is as per the following Table 1-1.

2. Type of the road security mirrors

Table 1-1 Type of road security mirrors

Shape of mirror face	Number of mirrors
Round surface	One-way mirror 2-way mirror

Note) One-way mirrors can be used on usual runways. At road junctions, you can use one-way mirrors if you need to check one direction only but you’ll need to use 2-way mirrors if you need to check 2 different directions.

3. Material of mirror face, selection of mirror size and radius of curvature

The size and the curvature radius of mirror face have something to do with the image size and visibility. If mirror face and curvature radius is large, you’ll have narrower view to see larger image. If mirror face and curvature radius is small, you’ll have wider view to see smaller image which makes it difficult to distinguish objects properly.

Therefore, the selection of mirror size and curvature radius shall be based on the figures

shown in table 2-1. However, it is also necessary to select adequate size of mirror depending on the road situation of the installation site.

Table 2-1 Size and curvature radius of mirror face (unit: mm)

Shape of mirror	Material of mirror	Size of mirror face	Curvature radius of mirror face
Circle	Stainless (SUS)	∅1000 ∅800 ∅600	Over 3,600 3,000 2,200

4. Selection of mirrors

1. How to select mirrors

The most important points in the selection of mirrors is that

- securing good reflexibility of the mirror face to increase visibility

- securing mirrors with precise curvature of the mirror face in order to avoid any image distortion

- selecting adequate size of mirror in consideration of the road width

- selecting mirrors of high visibility which can show objects placed in the area that needs to be

 confirmed. 

2. Selection of mirror size

Selection of mirror size shall be made depending on shape of mirror, size and material which are shown in Table 4-1.

Table 4-1 Thickness standards of mirrors (unit: mm)

Shape of mirror	Size	Thickness	Material
Circle	∅1000	1mm	Stainless mirror 304
	∅800	0.9mm
	∅600	0.9mm

5. Size of the post and security sign

1. Specifications of the post and security sign

There are several kinds of posts such as ground post, anchor post, band post and wall-mount post and the selection can be made depending on the situation of the installation site and as per Table 5-1 below.

And traffic direction signs such as arrow signs can be attached on the posts to enable drivers and pedestrians to proceed safely.

Yellow colored reflexive/ fluorescent arrow signs can secure safety at night time and their sizes are 450X600 or 300X450.

Table 5-1 Specification of post material (unit: mm)

Post options	Size	External diameter	Thickness	Length
Ground post	3000x76.3	76.3	3.2	3000
Anchor post	2500x76.3	“	“	2500
Band post	300x150x76.3	“	“	230
Wall-mount post	180x76.3	“	“	230

2. Color of the post

In principle, the color of the post shall be orange or white.

6. How to install security mirror

1. The location and how to install mirror.
The mirror shall be placed at the locations from where passing cars, pedestrians and obstacles are easily seen. And be sure that the mirror face or the post shall not hinder passing of cars.

The height from the bottom of mirror to the ground level is normally 1.8 meter.

The direction sign or the arrow sign shall be attached at the same angle as the mirror face.

2. Mirror angle
Mirror angles of up and down, left and right shall be adjustable depending on the scope of visibility. The angles shall be decided in consideration of all the different factors such as eye height of adults and children and from big cars or small cars.

For adequate installation, you can refer to the Diagram 1 below.

Diagram 1  Install angle of mirror

3. Post basic dimension and installation example  

The basic of security mirror shall be designed and made in consideration of the weight of the mirror itself and the weight under the influence of wind.

For adequate installation, please refer to the Table 6-1 and Diagram 2 below.

Table 6-1 Basic dimension of post

Mirror size	Basic dimension
∅1000 ∅800 ∅600	600(H) X 500

Diagram 2  Mirror install example

Ground post

1 way mirror post	2 way mirror post

Cliff wall post	Wall-mount post	Guard rail post

4. Installation

1) Safety Measures before installation

You must take necessary safety measures for drivers, pedestrians and workers before the installation.

2) Procedure of the installation

Location and procedures must be carried out according to the blueprint and the specifications herein.

3) Locate the place where the mirror is about to be set up.

You must consult the concerned authorities about the locations of underground water/ gas pipes or electrical/ telephone lines.

4) Dig out earth to get a hole that is 400 mm x 400 mm wide, and 700 mm deep to bury the post.

5) Fill the hole with pebbles or stones up to 100 mm from the bottom and press the layer of pebbles to prevent void space or collapse after construction.

6) Assemble the mirror with the bracket and then cover the top part of the post with a rubber cap.

7) Pour concrete. The post must stand upright until the concrete hardens completely.

If necessary, the chemicals accelerating the hardening of concrete may be added to the concrete mixture.

The post must be cleared of any foreign body and be kept upright during concrete pouring into the hole.

8) After concrete is hardened, position the mirror at the desired reflection angle and tighten the bolts completely.

9) Removal of safety measures

After installation is completed, clear the installation site and remove the safety measures.

10) Maintenance

Mirrors must be checked up periodically and maintained at the same condition as the time of their first installation.

A check-up must include the following points.

- Deformation

- Angle loosening or break-away

When a repair is necessary, the mirrors must be repaired according to the procedures mentioned above.