IRC 26:1967 is the Indian Standard (IRC) for report containing the code of practice for erection of kilometre stones and 200-metre stones. IRC 26:1967 specifies design, materials, and installation of kilometre stones, 200-metre stones, and route reference markers — the wayfinding infrastructure that helps drivers understand location and remaining distance on Indian highways. Traditionally kilometre stones were cast-iron; modern practice uses RCC for durability. Standard dimensions: kilometre stone 600 × 300 × 100 mm; 200-metre stone 450 × 200 × 75 mm. Placement: 2.0 m from road centerline on left side. Colour scheme varies by road type: NH green, SH yellow, MDR blue. Inscription in 3 languages (Hindi + state + English), with retroreflective sheeting for night visibility. Amendment No. 1 (2015) added standardized NH shield design (blue background with NH number); Amendment No. 2 (2022) added GPS-enabled smart milestones with QR code linking to route information. Despite the code's availability, many Indian roads have missing, damaged, or inconsistent kilometre stones — undermining driver wayfinding. Modern trend: replace traditional stones with digital/electronic signage on expressways, but traditional stones remain relevant for NH/SH/rural roads.
Specifies type designs, material specifications, siting, and installation methodology for kilometre stones, 200-metre stones, half-kilometre markers, and route reference markers on Indian highways.
Key reference values — verify against the current code edition / project specification.
| Reference | Value | Clause |
|---|---|---|
| Kilometre stone | At every 1 km, route/distance legend | Siting |
| 200-metre stone | At every 200 m between km stones | Siting |
| 5th-km / special stones | Distinct design at 5-km / boundary points | Siting |
| Material | Stone/precast concrete, painted to standard | Materials |
| Legend | Standard letters/numerals (see IRC 30) | IRC 30 |
| Placement | Set distance from carriageway edge, visible | Installation |
IRC 26 (1967) provides the Report Containing the Code of Practice for Erection of Kilometre Stones and 200-Metre Stones — the IRC's specification for roadside distance markers + chainage stones on Indian roads. Despite the 1967 vintage, these stones remain a feature of every Indian highway + are still installed on PMGSY rural roads + state-PWD highways.
Use IRC 26 when you are: - Specifying kilometre stones + 200-metre stones on NH/SH/district roads - Doing road project DPR that includes chainage marking - Designing distance markers + directional signs - Specifying PMGSY rural road chainage system - Coordinating roadside infrastructure positioning
What IRC 26 covers: - Kilometre stone dimensions + design - 200-metre stone dimensions - Material specifications (concrete, masonry) - Installation procedures - Marking + numbering conventions - Maintenance + replacement
Stone types: 1. Kilometre stone: at every kilometre; large; with chainage + destination 2. 200-metre stone: at every 200 m between kilometre stones; smaller marker 3. Boundary stone: at state / district boundaries 4. Project marker: at start / end of NH segments
Functions: - Distance marker: for drivers to know chainage - Reference point: for maintenance + emergency services - Navigation aid: especially in rural areas without GPS coverage - Project documentation: as-built records reference - Cultural / historic (some old stones are monuments)
Modern reality: - Many NH stones replaced or supplemented by signage - Reflective markers more common at high-speed roads - GPS + smart navigation reduce stones' navigational role - Stones still installed on rural / PMGSY roads + state highways - Heritage / tradition preserved in places
Kilometre stone: - Height above ground: 0.6-0.8 m - Top: rounded or hemispherical (~150-200 mm radius) - Width: 200-300 mm (top); slightly wider base - Below ground: 200-300 mm buried - Total length (including buried): 0.8-1.1 m - Material: RCC, masonry, or stone (M20-M25 grade for RCC)
Inscription (kilometre stone): - Top face: road name (NH-44 or SH-XX) + place name - Side faces: kilometre + direction (e.g., 'CHENNAI 250 km') - Lettering: painted; renewed periodically - Color: white background with black lettering
200-metre stone: - Smaller than kilometre stone - Height: 0.3-0.4 m above ground - Width: 100-150 mm - Below ground: 100-150 mm - Simple chainage marking only
Materials: - Pre-cast RCC: M20-M25 grade; reinforced; durable - Masonry: stone + cement mortar; traditional - Cast-in-place: at site if no pre-cast available - Coating: white-painted for visibility + waterproofing
Installation: - Foundation: dug to design depth + level - Sub-base: crushed stone or sand layer 50-100 mm - Stone placement: vertical + aligned to road - Filling around stone: compacted soil - Final paint + lettering
Location: - Lateral position: 1-2 m off carriageway edge - At kilometre marks: every 1 km (1+000, 2+000, etc.) - At 200-metre marks: every 200 m between km stones - At project boundaries: start / end of NH section
Lettering + numbering convention: - Chainage: km + 100 m units (e.g., 145+200 for 145 km + 200 m) - Direction: to nearest major destination - Road designation: NH-44, SH-12, etc. - Bilingual: English + local language (Hindi / regional)
Paint specification: - Background: white paint (acrylic or anti-fade) - Lettering: black paint - Reflective dots / strips on top (modern enhancement) - Renewal frequency: every 2-3 years
Maintenance: - Monthly visual inspection - Annual cleaning + repainting - Replacement of damaged stones (vehicle impacts, vandalism) - Coordination with road maintenance
Modern alternatives: - Reflective marker posts on high-speed roads - Digital signage with chainage display - GPS-based positioning for navigation - QR codes on stones for vehicle / emergency reference
Service life: - RCC stone: 25-50 years - Masonry: 20-40 years - Paint: 2-3 years (refreshed) - Stone is permanent feature of road infrastructure
Kilometre stone dimensions: - Above ground height: 0.6-0.8 m - Top width: 200-300 mm - Base width: 250-350 mm (slightly wider for stability) - Below ground: 200-300 mm buried (foundation) - Total length: 0.8-1.1 m
200-metre stone: - Above ground height: 0.3-0.4 m - Width: 100-150 mm - Below ground: 100-150 mm - Total length: 0.4-0.55 m
Material: - RCC: M20-M25 with reinforcement - Masonry: stone + 1:6 cement mortar - Stone (natural): granite, sandstone, basalt (regional) - Pre-cast: factory cast for consistency
Reinforcement (RCC stone): - 4 × 12 mm bars - 8 mm stirrups at 150 mm c/c - Concrete cover: 25 mm
Foundation: - Depth: 200-300 mm - Sub-base: 50-100 mm crushed stone - Cement-mortar bonding between stone + foundation
Letter height: - Place name: 25-50 mm - Chainage number: 50-100 mm - Direction arrow: as needed - Per IRC:30:1968 for visibility
Color: - Background: white (matt finish) - Lettering: black - Top reflective dot/strip: yellow / amber for night visibility
Spacing + placement: - Kilometre stones: every 1 km - 200-metre stones: every 200 m between km stones (i.e., at 200, 400, 600, 800) - Lateral offset: 1-2 m from carriageway edge - In curves: on inside of curve preferred
Installation tolerances: - Position: ± 100 mm of design chainage - Vertical alignment: ± 10 mm out of plumb - Lateral offset: ± 100 mm of design - Top level: consistent (no random heights)
Acceptance: - Dimensions per design - Material quality (concrete strength, masonry workmanship) - Lettering legibility + accuracy - Stable installation - Aesthetics acceptable
Maintenance schedule: - Monthly visual: check damage, alignment - Annual: cleaning + repainting - As needed: damaged stone replacement - Per state PWD / NHAI maintenance contracts
Cost: - Per kilometre stone: ₹3,000-8,000 typical - Per 200-metre stone: ₹1,000-3,000 typical - Maintenance per stone: ₹500-1,500 per year (cleaning + repainting)
Modern enhancements: - Reflective accessories on stones - GPS chainage signs at km locations - QR codes for vehicle / emergency reference - LED-illuminated at strategic locations - Smart sensors for traffic counting (research)
1. Stones missing on stretches. Drivers + emergency lose chainage reference. Every km + 200 m mandatory. 2. Damaged stones not replaced. Cumulative damage; chainage system breaks. Maintenance + replacement. 3. Lettering faded. Stones unreadable. Repainting every 2-3 years. 4. Stones in wrong position. Chainage off; misleads users. Survey + accurate placement. 5. Material substandard. Low-grade concrete; quick degradation. Per IS 456 grade. 6. Stones obstruct sight. At intersections / curves. Place outside sight zone. 7. No reflective enhancement. Night invisibility. Reflective accessories. 8. Vegetation overgrowth. Stones obscured. Maintain clearance. 9. Inconsistent dimensions. Some stones larger, some smaller; visual chaos. Standardise per design. 10. No road safety audit. In-service issues. Per IRC:SP-44:1996. 11. Stone placement disrupts pedestrian path. On footpath. Coordinate with footpath design. 12. Stones not durable. Quick degradation in harsh climate. Quality materials + protective coating. 13. Numbering errors. Chainage on stone doesn't match actual. Survey verification. 14. Bilingual inconsistency. English + local language differ. Verify both. 15. Heritage stones not preserved. Old stones with cultural value lost. Preservation policy. 16. No coordination with maintenance. Stones not in maintenance contract. Include in budget. 17. Materials don't suit climate. Limestone in acidic environment; chemical attack. Climate-appropriate materials.
Kilometre stone project — IRC 26 touchpoints:
1. DPR / design: - Stone schedule (every km + 200 m) - Material + dimensions per IRC 26 - Lettering + content design - Placement coordination with road geometry
2. Pre-construction: - Survey + chainage establishment - Stone manufacturing or procurement - Site marking for installation
3. Manufacturing / procurement: - Pre-cast factory (preferred) or cast-in-place - Quality control - Lettering / numbering
4. Installation: - Foundation excavation - Stone placement + alignment - Backfill + compaction - Painting + final inspection
5. Acceptance: - Position verification (chainage accuracy) - Visual inspection - Final paint quality
6. Operations + maintenance: - Monthly visual check - Annual cleaning + repainting - Damage replacement - Per maintenance contract
7. Long-term: - Stones replaced gradually as needed - Material upgrade options - Modern enhancement (reflective, GPS, QR) - Heritage preservation where applicable
IRC 26 is the enduring road-furniture reference for India's distance-marking system — applied on every NH / SH / PMGSY / state-PWD road in India, providing tangible chainage reference for over 50 years.