Highway signage is a regulated category of its own. Where building and outdoor signage operates under municipal bye-laws, signage along national highways operates under the framework set by the Ministry of Road Transport and Highways and implemented by the National Highways Authority of India. The IRC codes — particularly the IRC:67 code on traffic signs and IRC:30 on standards for direction and place identification signs — define the technical specifications, while the NHAI's policies define which categories of signage are permitted within the right of way and on adjoining land. For procurement teams installing signage along highway corridors, this framework determines what is technically and legally possible.
The right of way along a national highway is the strip of land along the highway that is acquired and managed by the highways authority. The width of the right of way varies by highway category and corridor history but is typically in the range of forty-five to sixty metres. Within the right of way, only traffic signs, directional signs, place identification signs, and other signage authorised by the highways authority are permitted. Commercial advertising signage within the right of way is generally not permitted, and unauthorised signage is removed by the authority during periodic enforcement drives.
Outside the right of way, on private land along the highway, commercial signage is permitted subject to the local body's outdoor advertising policy and to specific NHAI guidelines on safety. The safety guidelines address the visibility distance from the highway, the illumination characteristics that should not distract drivers, the structural setback from the highway edge to prevent any debris from a structural failure reaching the carriageway, and the height limits that prevent signage from interfering with the highway's own directional signage. Signage operators along highway corridors typically maintain documentation showing that their structures are outside the right of way and that they comply with the safety guidelines.
For traffic signs themselves — the regulatory, warning, and informatory signs that direct highway users — the IRC:67 code defines the shapes, colours, sizes, retroreflective requirements, and installation specifications. Regulatory signs are circular, in red and white. Warning signs are triangular, in red and white. Informatory signs are rectangular, in green and white or blue and white depending on category. Each sign type has a defined size for the corresponding highway speed regime and lane configuration. The retroreflective sheeting on the sign face must meet specified performance grades — typically Type IV or higher microprismatic sheeting for high-speed corridors — to ensure visibility under headlight illumination at night.
Direction and place identification signs are the more complex category. The IRC:30 code addresses the layout, lettering, advance distance signing, exit signing, and distance signing on highway corridors. The lettering uses defined fonts at defined heights based on viewing distance. The colour combinations are standardised. The arrangement of multiple destinations on a single sign follows specified rules to maintain readability at highway speeds. Procurement teams supplying direction signs to highway projects need vendors who are familiar with the IRC:30 conventions and who can produce drawings that match the highway authority's typical specifications.
The substrate for highway signage is typically aluminium composite material or aluminium sheet, with the retroreflective sheeting laminated to the face. The substrate gauge, the edge treatment, the post arrangement, and the foundation design are all specified to withstand the wind loads at the installation location and to prevent the sign from becoming a hazard if struck by a vehicle. The sign post is often a breakaway design that yields under impact rather than transferring the energy back into the vehicle. Procurement specifications for highway signage need to address all of these structural elements, not just the visible face of the sign.
The NHAI maintenance regime for highway signage covers cleaning, replacement of damaged retroreflective sheeting, repainting where required, and structural integrity inspection. Signage along an operational highway is exposed to vehicle impact, weathering, vandalism, and dust accumulation. The retroreflective performance degrades over time and needs periodic measurement using a retroreflectometer to confirm continued compliance with the specified grade. Where measurements show degradation below the threshold, the affected sheeting is replaced. The maintenance contracts that NHAI awards for highway corridors typically include the signage maintenance scope, with the maintenance contractor responsible for keeping the signage population in compliance.
For private operators along highway corridors — fuel stations, food courts, hotels, motels, and the various roadside services that have grown along major highways — the signage scope includes both the operator's own brand signage on their property and the wayfinding signage that directs highway users to the facility. The wayfinding signage is sometimes integrated into the highway authority's own signage program through specific service signage schemes; a fuel station near a highway exit may have its identity included on an authority-installed informatory sign for highway users approaching the exit. Where this integration is not available, the operator installs their own signage on private land along the approach to the facility, subject to the safety guidelines.
The technical specifications and material grades for highway signage have evolved over the last several years toward more durable materials, brighter retroreflective performance, and more standardised messaging. Microprismatic sheeting at higher performance grades has become the norm for new installations on national highway corridors, replacing the engineering-grade sheeting that was common earlier. Procurement specifications for new highway signage should match the current grade expectations rather than defaulting to older specifications that the highway authority no longer accepts on its own work.
For commercial brands placing signage along highway corridors, the practical compliance approach is to work with the local body that has jurisdiction over the land where the signage is being placed, rather than treating the highway authority as the approval body. The highway authority's role on private-land signage is to enforce safety setbacks and visual interference restrictions, not to grant the underlying permission. The permission comes from the local panchayat, municipality, or municipal corporation under whose jurisdiction the land falls. Procurement should clarify this jurisdictional point at the start of any highway corridor signage program, because submitting the application to the wrong authority causes weeks of delay before the application is forwarded or rejected.
The fabrication and installation of highway signage requires specific capabilities. The retroreflective sheeting needs to be applied in a controlled environment to prevent dust contamination of the adhesive. The substrate needs to be cleaned and primed before sheeting application. The lettering and graphics are typically cut from coloured retroreflective vinyl and applied to the base sheeting rather than printed, because printed graphics on retroreflective sheeting do not retroreflect through the printed area. The installation involves traffic management on the live highway during the work, with appropriate barricading and warning signage. Sushant Industries fabricates and installs signage scopes that include directional and informatory components for industrial and commercial clients along highway corridors, drawing on the infrastructure overview and the project documentation visible on /works.
The summary view for procurement teams scoping highway corridor signage is that the technical and regulatory framework is mature and well-documented but specialised. A vendor with documented experience in highway-grade signage — including retroreflective material handling, IRC-compliant layout, structural design for wind and impact loading, and traffic management during installation — is the right partner. A vendor whose normal scope is building facade signage will struggle on a highway scope until they invest in the additional capability. Procurement should validate this capability through reference projects and through the vendor's documented compliance with the relevant IRC codes before placing the order.
