Route Marker Signs for State Routes

The Introduction of IRC 31 provides foundational guidance on letter and numeral specifications for road signs. Key points include:

• Letter and numeral sizes, shapes, and spacing must conform to Fig. 1 and Plates 1, 5, and 6 as per Clause 2.3.
• TABLE 1 presents a letter-to-letter code number system used to determine spacing between letters.
• TABLE 2 (Solcing Between) is referenced for spacing details, measured horizontally from the right edge of the preceding letter to the extreme left edge of the following letter.

The provided TABLE 1 is as follows:

This coding helps standardize letter spacing for legibility on signs.

For exact letter shapes and sizes, refer to the specified figures and plates in the code.

Sources: Clause 2.3, TABLE 1, TABLE 2

In IRC 31, all dimensions are specified in millimetres. For materials and finishes related to lettering and numerals, the size, shape, and spacing must conform to Fig. 1 and Plates 1, 5, and 6 as per the code. The key specification for spacing between letters is given in TABLE 1 and TABLE 2, which provide letter-to-letter code numbers and corresponding spacing values. The spacing between letters is measured horizontally from the right edge of the preceding letter to the extreme left edge of the following letter. The code number from TABLE 1 is used to determine the spacing from TABLE 2.

Here is the reproduced table for letter-to-letter code numbers and spacing:

This ensures uniformity in materials and finishes for signage as per IRC 31 requirements.

Sources: Clause 2.3, TABLE 1, TABLE 2

According to IRC 31, the key specifications for State Route Marker Signs are as follows:

• The marker sign consists of a shield mounted on a rectangular plate measuring 450 mm by 600 mm (Clause 2.1).
• The detailed design of the shield is provided in Plate 1 of the code.
• The erection arrangement for these signs is specified in the drawing titled "Arrangement for Erection of State Route Marker Signs", Plate 2 (Clause 3.2).

No explicit formulas are provided in the retrieved context. The dimensions and arrangement drawings are the primary design references for these signs.

Sources: Clause 2.1, Clause 3.2

The Definition Plate in IRC 31 specifies that the size, shape, and spacing of letters and numerals must conform to the details provided in Fig. 1 and Plates 1, 5, and 6 as per Clause 2.3. Additionally, typical arrows used on the Definition Plate are detailed in the code, ensuring standardized marking. These specifications ensure clarity and uniformity in the identification plates used in road and bridge works.

Sources: Clause 2.3

The IRC 31 code section on Route Marker Assembly at Junctions with Numbered Routes specifies the arrangement and placement of route markers where state routes intersect with other numbered routes. Key points include:

• Route markers must be clearly visible and positioned to guide drivers effectively at junctions.
• Assemblies typically include the state route marker combined with the intersecting numbered route markers.
• A plan showing the exact location of the route marker sign at the junction is required to ensure proper visibility and compliance.

Unfortunately, the retrieved context does not provide explicit formulas or detailed tables for these assemblies. For precise dimensions, layout, and specifications, refer to the full IRC 31 document sections on route marker assemblies and junction signage.

If needed, typical practice involves mounting route markers on posts at junctions with clear directional arrows and standardized sizes for visibility.

Sources: Clause None: 5. ROUTE MARKER ASSEMBLY AT JUNCTIONS WITH NUMBERED ROUTES

As per IRC 31, the back of all route marker signs shall be painted in unobtrusive grey, specifically Indian Standard Colour No. 630. The sign post must be painted in alternating 25 cm bands of black and white, with the lowest band next to the ground being black. Additionally, the background colour of the definition plate is white, with the border and arrow in black. For background green, Indian Standard Colour No. 221 is specified.

Sources: Clause 6, Clause 4.2

For positioning State Route Marker Signs at junctions, IRC 31 specifies that a definition plate of size 300 mm by 250 mm shall be fixed below the shield to indicate the direction of the State Route at the junction, as per Clause 4.1. The arrangement for erection follows the drawing titled "Arrangement for Erection of State Route Marker Signs" (Plate 2) per Clause 3.2.

Regarding lettering spacing on signs, the code provides a method using TABLE 1 and TABLE 2 (partially retrieved) to determine horizontal spacing between letters. The spacing is measured from the right edge of the preceding letter to the extreme left edge of the following letter. TABLE 1 assigns code numbers to letter pairs, and TABLE 2 translates these codes into spacing values in millimeters (e.g., code 2 corresponds to 15 mm, code 3 to 10 mm, code 4 to 5 mm, etc.). This ensures consistent and legible letter positioning on signs.

Summary:

• Definition plate size: 300 mm × 250 mm (Clause 4.1)
• Letter spacing determined by letter pair codes (TABLE 1) and spacing values (TABLE 2)
• Spacing measured horizontally from letter edges

| Letter Pair Code | Spacing (mm) |
|------------------|--------------|
| 2                | 15           |
| 3                | 10           |
| 4                | 5            |

This ensures proper positioning and clarity of sign lettering at junctions.

Sources: Clause 4.1, Clause 3.2, TABLE 1, TABLE 2

For roads with kerbs, the installation guideline specifies placing elements less than 60 cm from the edge of the kerb. For roads without kerbs, the guideline indicates a distance of 2.70 to 3 m from the road edge. Additionally, route markers must be erected as per the drawing titled "Arrangement for Erection of State Route Marker Signs", Plate 2, as per IRC 31. These specifications ensure proper placement for safety and visibility along the road.

Summary:

• Roads with kerbs: Installation within < 60 cm from kerb edge
• Roads without kerbs: Installation at 2.70 to 3 m from road edge
• Route markers: As per Plate 2 drawing in IRC 31

No detailed formulas or tables were provided in the retrieved context for installation distances or specifications.

Sources: Clause None: t, Clause None: 2, Clause None: 3.2

For spacing and arrangement of numerals and letters as per IRC 31, the key method is to obtain the code number from Table 1 (Letter to Letter Code Number) and then use Table 2 to determine the proper spacing between letters or numerals. The spacing is measured horizontally from the extreme right edge of the preceding letter/numeral to the extreme left edge of the following one. Table 1 provides code numbers for letter pairs, and Table 2 translates these code numbers into spacing values in millimeters. Additionally, the size, shape, and spacing of letters and numerals must conform to the specifications given in Fig. 1 and Plates 1, 5, and 6 of IRC 31. For example, spacing between standard numerals of 10 cm height is specified but the exact value is not fully visible in the context.

Here is the reproduced Table 1 and Table 2 from the context:

This system ensures consistent and legible spacing for numerals and letters on signs or markings.

Sources: TABLE 1 LETTER TO LETTER CODE NUMBER, TABLE 2 SPACING BETWEEN LETTERS, Clause 2.3

According to IRC 31, key specifications for sign assemblies include:

• A 'State Route' marker sign consists of a shield on a rectangular plate sized 450 mm by 600 mm as per Plate 1 (Clause 2.1).
• When erected at a junction, the direction of the State Route at the junction must be indicated on a definition plate sized 300 mm by 250 mm, fixed below the shield (Clause 4.1).
• The erection of route markers must follow the arrangement shown in the drawing titled "Arrangement for Erection of State Route Marker Signs" (Plate 2) as per Clause 3.2.

No explicit formulas are provided in the retrieved context. The key details are the dimensions and arrangement of the sign assemblies as per the referenced plates.

Sources: Clause 2.1, Clause 3.2, Clause 4.1

For maintenance and visibility considerations in IRC 31, the key specifications relate to the size, shape, and spacing of letters and numerals to ensure clear legibility. As per the context, the size, shape, and spacing shall conform to Fig. 1 and Plates 1, 5, and 6 (Clause 2.3). The spacing between letters is determined using a code number from TABLE 1, which provides letter-to-letter code numbers for spacing. TABLE 2 specifies the horizontal spacing between letters measured from the right edge of the preceding letter to the extreme left edge of the following letter. Additionally, dimensions for letters of various heights in millimeters are provided to standardize visibility. These tables ensure that letters on signs are spaced and sized for optimal visibility and maintenance ease.

Sources: Clause 2.3, TABLE 1 LETTER TO LETTER CODE NUMBER, TABLE 2 SPACING BETWEEN LETTERS