IRC (Indian Roads Congress)

Indian Roads Congress (IRC) is the apex professional body governing road and bridge engineering practice in India. IRC publishes codes, standards, manuals, and special publications covering all aspects of highway and bridge engineering — from design loads and structural analysis to construction practices, maintenance, and performance evaluation. Major IRC publications: IRC 6:2017 (loads and stresses for road bridges), IRC 24:2010 (steel bridges), IRC 37:2018 (flexible pavement design), IRC 58:2015 (rigid pavement design), IRC 73:1980 (geometric design of rural highways), IRC 78:2014 (foundations of bridges), IRC 86:2018 (geometric design of urban roads), IRC 112:2020 (concrete bridges).

IRC code framework: (1) IRC 'main' codes — primary standards for design and construction (e.g., IRC 6 for loads, IRC 112 for concrete bridges). (2) IRC SP (Special Publications) — detailed guidance documents (e.g., IRC SP 13 for small bridges, IRC SP 20 for rural roads, IRC SP 84 for four-laning). (3) IRC HRB (Highway Research Bulletin) — research papers and case studies. (4) IRC manuals — operational documents for specific topics. The total IRC code corpus contains 100+ documents covering Indian road and bridge engineering. IRC codes are mandatory for highway projects in most states; many state PWDs and the Ministry of Road Transport and Highways (MoRTH) reference IRC standards.

Distinction from IS codes: IS codes (Bureau of Indian Standards) cover general civil engineering — concrete, steel, masonry, foundations, loads. IRC codes specifically cover roads, bridges, highways, and related infrastructure. The two systems are complementary — IRC bridges use IS 456 for concrete and IS 800 for steel as supplementary references. For any highway or bridge project: IRC codes govern road geometry, pavement, drainage, structures (with IS supplementary). For any general building or non-highway structure: IS codes govern primarily. Major Indian highway projects routinely use the IRC framework: IRC 6 + IRC 24 / 112 (depending on bridge material) + IRC 37 / 58 (depending on pavement type) + IRC SP 84 (four-laning standards).