IRC 35 : 2015Code of Practice for Road Markings

IRC 35 is the Code of Practice for Road Markings — the authoritative document for every painted, thermoplastic, cold-plastic, or pre-formed marking laid on a public road in India. It is referenced by NHAI, MoRTH, state PWDs and municipal corporations in their road-furniture BOQs, and by the IRC's wider road safety toolkit (IRC SP 55:2014, IRC 99, etc.).

Use IRC 35 when you are: - Preparing the road-furniture BOQ for any highway / urban road / rural road project - Designing a road safety audit recommendation list - Specifying lane discipline + speed-change zones on NH / SH widening projects - Marking pedestrian / school / hospital zones in city DCRs - Re-painting existing markings (maintenance contracts) - Designing intersection / roundabout / toll-plaza geometry — markings are the lowest-cost traffic-control measure - Procuring marking materials (paint, glass beads, retro-reflectivity criteria)

What IRC 35 covers: - Longitudinal markings (centre line, edge line, lane line) - Transverse markings (stop line, give-way, pedestrian crossing, speed-table, rumble strip) - Object hazard markings (kerbs, gore areas, traffic islands) - Word/symbol markings (SLOW, STOP, school, arrows, bus lane) - Material specifications (paint, thermoplastic, cold plastic, pre-formed tape) - Retro-reflectivity (initial + service-life thresholds) - Dimensions, colour, layout, spacing - Re-marking intervals + maintenance criteria

Longitudinal markings (lane direction, in metres): - Centre line on single-carriageway: broken white, 3 m line / 6 m gap (50/50 on high-speed roads). Standard width: 100-150 mm. - No-overtaking zone: continuous yellow centre line (or double yellow on undivided two-way). - Lane line on divided / multi-lane: broken white, 3 m line / 4.5 m gap. - Edge line (carriageway edge): continuous white, 100-150 mm wide, 100-200 mm inside the kerb / shoulder. - Approach to hazard (curve, intersection): centre line goes continuous at least 50 m ahead.

Transverse markings: - Stop line: continuous white, 300 mm wide, 1-3 m ahead of the conflict point. - Give-way line: broken white double line, 200-300 mm each, ~1 m gap, 600 mm before conflict. - Zebra (pedestrian) crossing: parallel white bars 500 mm wide, 500 mm gap, total length usually 2.5-3 m across the carriageway. Bar spacing varies by speed (longer bars / wider gaps on higher-speed approaches). - Speed-table / rumble strip: prefer thermoplastic with grooves for tactile feedback; geometry by IRC SP 32 (traffic-calming).

Colour code: - White = directional, lane discipline, regulatory (most markings) - Yellow = no-overtaking, kerb hatching, bus-only lanes, school zone, narrow centre divider - Red/orange = temporary diversion (construction zone) - Blue = hospital, disabled-access (urban use)

Material thickness — paint vs thermoplastic vs cold plastic: - Conventional paint (alkyd / acrylic emulsion): dry-film 150-200 µm; service life 6-12 months on high-traffic NH. - Hot-applied thermoplastic: 2.5-3.5 mm thick (extruded); typical service life 2-4 years. - Pre-formed (factory-cast) thermoplastic: 3 mm; used for symbols + crossings. - Cold-applied plastic (MMA / polyurea): 0.6-1.5 mm; service life 3-5 years in heavy traffic. - Pre-formed pavement tape: 1.5 mm; for short-term/temporary use.

Retro-reflectivity (mcd/m²/lx): - Initial (new marking, white): ≥ 250 mcd/m²/lx dry; ≥ 100 mcd/m²/lx wet (high-spec NH). - Initial (yellow): ≥ 175 mcd/m²/lx dry. - Maintenance threshold (re-marking required when below): 100 mcd/m²/lx for white, 75 mcd/m²/lx for yellow. - Glass beads: 250-300 g/m² drop-on; intermix bead 18-22 % by weight in thermoplastic.

Width tolerance: ± 5 mm on stripe width; ± 50 mm on length per IRC SOR.

Application conditions: - Pavement surface temperature: 10-40 °C (paint), 10-50 °C (thermoplastic at ambient — material itself at 180-200 °C application). - Surface dry, free of dust/oil/laitance; min 2 hours after last rain. - New bitumen surface: cure period ≥ 14 days before final marking; new concrete: ≥ 28 days + acid etch.

Skid resistance (BPN): marking surface should have ≥ 45 BPN to match carriageway; achieved with anti-skid aggregate / textured tape.

Hot-thermoplastic mix composition (typical): - Binder (resin): 18-22 % - Filler (calcium carbonate / silica): 35-45 % - Glass beads (intermix): 18-22 % - Pigment (titanium dioxide for white): 6-10 %

• IRC:67:2012 — Code of Practice for Road Signs. Markings + signs are designed together; sign positions reference stop lines / give-way lines from IRC 35.
• IRC SP 55:2014 — Guidelines for Traffic Management in Work Zones. Temporary markings on diversions follow IRC 35 material + retroreflectivity rules.
• IRC SP 99:2013 — Manual of Specifications and Standards for Four Laning of Highways. Includes lane markings on NH 4/6-lane sections.
• IRC:99:2018 — Tentative Guidelines on the Provision of Speed Breakers. Speed-table marking dimensions from IRC 35.
• IRC SP 32 — Guidelines on Traffic Calming Measures. Marking patterns for tabletops, raised crossings.
• IRC:65:2017 — Recommended Practice for Traffic Rotaries. Roundabout entry/exit markings.
• IRC SP 102 — Guidelines for Pavement Marking Materials.
• IRC SP 12 — Tentative Guidelines on Reflectorisation of Road Markings.
• IS 164 — Specifications for Ready Mixed Paint for road markings.
• IS 1660 — Methods of Test for road marking paint.
• BS EN 1436 — European standard frequently referenced for retro-reflectivity test methods (Indian OEMs often quote both).
• MoRTH Specifications for Road and Bridge Works — Section 800 (Traffic Signs, Markings, Other Road Appurtenances); Sub-section 803 specifically on markings.
• Indian Roads Congress Manual on Road Safety Audit — uses IRC 35 as the marking-compliance reference.

1. Paint on green bitumen surface. Marking peels in 3-4 months because BC layer hasn't fully cured. Wait minimum 14 days after wearing-coat laying. 2. Thermoplastic applied without primer on concrete. Bond failure within weeks. Always use primer (alkyd-based) on cement-concrete surface; not required on bitumen. 3. Bead drop rate too low. Initial retro-reflectivity meets spec, but service life drops to <6 months because surface beads abrade quickly. Specify 250-300 g/m² with proven equipment; check coverage during application. 4. Yellow centre line on speed-restricted curves used inconsistently. Designer marks yellow only where overtaking is fundamentally unsafe; IRC 35 requires it 50 m on approach to every hazard. Audit by drive-through. 5. No edge line on rural single-lane carriageways. Drivers don't perceive carriageway edge at night → off-road incidents. Edge line is mandatory on all carriageways > 3.5 m wide per IRC 35. 6. Marking width violates 100-150 mm range. Some agencies specify 75 mm to save cost; sub-spec, fails IRC 35. Stick to 100-150 mm (150 on high-speed roads). 7. Stop line placed too close to conflict. Drivers stop on the kerb / inside the intersection; visibility lost. Minimum 1 m clear to conflict, ideally 2-3 m. 8. Pedestrian crossing at high-speed location without speed-table / signal / signage support. Markings alone don't slow traffic; relying only on zebra is hazardous. Combine with signage, signals, or geometric calming. 9. No retro-reflectivity acceptance test at handover. Markings 'look new' but measured retro is below spec. Mandatory: retro-reflectometer test on minimum 10 sample points per kilometre at acceptance. 10. Re-marking intervals not scheduled in O&M budget. Marking degrades silently; safety degrades with it. Maintenance contracts must include retro-reflectivity inspection every 12 months with re-marking triggered at threshold. 11. Glass beads sieved away during cleaning. Mechanical sweepers strip surface beads in 2-3 passes; retro plummets. Specify intermix bead content + careful sweeping protocol. 12. Inconsistent colour between adjacent sections. Two contractors, two batches, two whites. Specify single supplier per project; insist on titanium dioxide pigment for whiteness consistency.

Road project lifecycle — IRC 35 touchpoints:

1. Concept / feasibility: road safety audit identifies marking gaps on existing roads, sets target retroreflectivity for new project. 2. DPR stage: marking BOQ derived from typical cross-section drawings; signs + markings designed together per IRC:67 + IRC 35. 3. Detailed design drawings: - Layout plan of all longitudinal markings (centre, edge, lane) - Layout of transverse markings (stop, give-way, zebras) - Special markings at intersections, school zones, bus stops, toll plazas - Marking schedule with material spec (paint vs thermoplastic), bead content, application thickness 4. Tender + award: specify IRC 35 + MoRTH 803 + measurement method (per square metre completed marking). Include retro-reflectivity acceptance threshold + payment hold-back if below spec. 5. Pre-marking site condition: verify surface temperature, dryness, age of bitumen, cleanliness. Reject if non-conforming. 6. Marking execution: - Setting-out + pre-marking layout (tape lines, paint dots) - Application as per material spec - Bead application (drop-on intermix) - Cure time (15-20 min thermoplastic, longer for paint) 7. Acceptance test: retro-reflectivity measurement at 10 points/km + visual + dimensional check. Issue defect notice if below threshold; replace at contractor cost. 8. Defects liability: retro-reflectivity criteria sustained over DLP; major degradation = contractor liable. 9. Operations + maintenance: - Annual retro-reflectivity audit - Re-marking when below maintenance threshold (100 mcd/m²/lx white) - Material upgrade decisions (paint → thermoplastic → cold plastic) based on AADT growth

IRC 35 is the single highest-impact road-safety document per rupee spent in Indian road construction — markings cost 0.5-2 % of project value but contribute disproportionately to driver guidance, lane discipline and night-time visibility.