IRC Classifications in Highway Engineering – Explained for JKSSB Aspirants -

The Indian Roads Congress (IRC) is the premier technical body responsible for evolving guidelines, standards, and specifications for road and highway construction in India. Established in 1934, it plays a pivotal role in shaping the national road network through its codes and recommendations. For every JKSSB civil engineering aspirant, a clear understanding of the IRC classifications of roads is essential, as this topic is frequently covered in objective and descriptive sections of competitive exams. Moreover, knowing these classifications helps build a solid foundation in highway engineering concepts relevant to both academic and practical field applications.

📘 What is IRC?

IRC Full Form: Indian Roads Congress
Established: 1934
Headquarters: New Delhi, India
Purpose: To provide guidelines, specifications, and standard codes for design, construction, and maintenance of roads and bridges in India. IRC plays a central role in ensuring uniformity and quality in highway engineering practices across all states. It also regularly publishes important codes such as IRC:37 for pavement design, IRC:15 for geometric design, and IRC:58 for rigid pavement design, which are vital references for engineers and exam aspirants alike.

🔍 Types of IRC Classifications of Roads

IRC classifies roads in two major ways:

1️⃣ Based on Traffic Volume (as per IRC:64-1990)

This classification is based on the number of vehicles per day (Veh/day), specifically focusing on Commercial Vehicles Per Day (CVPD). It is crucial for determining the thickness and composition of road pavement layers, ensuring roads are designed to withstand expected loads over time.

Classification	Traffic Volume (CVPD*)	Description	Road Design Features
NH – National Highway	>30,000	Heavy traffic	Multilane, rigid/flexible pavement, dividers, bypasses
SH – State Highway	10,000–30,000	Moderate to heavy	Two to four lanes, flexible pavement
MDR – Major District Road	5,000–10,000	Moderate traffic	Two lanes, flexible pavement, moderate shoulder width
ODR – Other District Road	1,000–5,000	Light to moderate	Single/two lane, bituminous/WBM surfacing
VR – Village Road	<1,000	Light traffic	Earthen/gravel roads, minimal engineering

CVPD: Commercial Vehicles Per Day
(Note: Exact numbers may vary slightly as per updated codes, but this table represents standard thresholds used for exam preparation.)

2️⃣ Based on Location and Function (IRC:73-1980)

This is the functional classification of roads. It’s based on the road’s importance in national, state, or local connectivity, and plays a key role in infrastructure development. It helps engineers and policymakers prioritize investment, set appropriate geometric standards, determine the required pavement thickness, and plan periodic maintenance schedules. Roads with higher functional importance, like NH and SH, are designed for heavier loads and higher speeds, while roads like ODR and VR serve local transport needs and are planned with basic construction features.

🟩 (a) National Highways (NH)

Connect major metropolitan cities, ports, industrial hubs, tourist centers, and international borders
Constructed and maintained by Central Government through agencies like NHAI (National Highways Authority of India)
E.g., NH-44 (longest highway from Srinagar to Kanyakumari), NH-48 (Delhi to Chennai via Mumbai and Bengaluru)
Designed with high-quality pavements, controlled access, bypasses, and interchanges for uninterrupted high-speed travel
Importance: Backbone of road transport in India, vital for economic integration, defense logistics, inter-state commerce, and national development

🔾 (b) State Highways (SH)

Connect state capitals with district HQs, NHs, tourist destinations, and important urban centers within the state
Constructed and maintained by respective State Governments through their Public Works Department (PWD)
Designed for medium to high-speed travel with adequate lane width, signage, and pavement quality
Serve as secondary roads to National Highways and act as feeders to the primary network
Importance: Facilitate regional trade, promote tourism, support administrative connectivity, and enhance intra-state development

🟨 (c) Major District Roads (MDR)

Link major commercial, industrial, and agricultural centers within a district
Connect to State Highways and other major roads to facilitate efficient distribution of goods and passenger movement
Moderate design speed, usually between 40–60 km/h, and flexible pavement design depending on expected traffic
Pavement types can vary from bituminous surface treatment to WBM depending on district budget and usage
Importance: Essential for intra-district movement, access to services such as education, healthcare, markets, and supporting district-level economic activities

🟧 (d) Other District Roads (ODR)

Provide connectivity between rural areas, agricultural farms, local markets, and tehsil headquarters
Support the movement of agricultural produce, villagers, and essential services such as milk collection, healthcare outreach, and rural education
Usually of lower construction standard, often single-lane or gravel roads with limited drainage and shoulder width
Importance: Play a critical role in rural development, last-mile connectivity, access to social infrastructure, and poverty alleviation programs

🔴 (e) Village Roads (VR)

Connect villages with each other and with higher-order roads
Often unpaved or lightly paved with earth, gravel, or low-grade bituminous surfaces
Used primarily for local movement, school transport, agricultural access, healthcare, and basic service delivery
Typically have narrow widths and minimal engineering features due to budget constraints
Importance: Grassroots connectivity and social inclusion, ensuring that even the most remote areas are accessible for development, emergency response, and government outreach

🧠 Tips for JKSSB Exam Preparation

Remember IRC:73 = Functional classification of roads based on their purpose and connectivity levels
IRC:64 = Traffic-based classification used for pavement design based on Commercial Vehicles Per Day (CVPD)
NH and SH = High capacity roads that form the national and state-level transport backbone, often multilane and well-maintained
VR and ODR = Low traffic roads serving rural and remote regions, generally with basic construction standards
Prepare short notes, use flowcharts to understand hierarchy, and revise classification tables frequently for quick recall in exams

📌 Mnemonic for Road Hierarchy (NH > SH > MDR > ODR > VR):

“No Strong Man Over Values” — This phrase helps aspirants quickly recall the decreasing order of road classification hierarchy as defined by the IRC.

National — Highest category of roads with the most strategic importance
State — Second-tier roads that link state-level hubs
Major District — Roads that serve within a district for moderate traffic
Other District — Roads connecting rural parts and local centers
Village — Lowest category, serving village-level access and basic mobility

📚 FAQs – IRC Classifications in Highway Engineering

Q1. What is the full form of IRC?
A: Indian Roads Congress

Q2. Which IRC code refers to road classification based on function?
A: IRC:73-1980

Q3. Which is the highest class of road in IRC classification?
A: National Highways (NH)

Q4. What is CVPD?
A: Commercial Vehicles Per Day – used in traffic-based classification.

📈 Conclusion

Understanding the IRC classifications of roads is fundamental for every civil engineering student and JKSSB aspirant. It not only forms the basis of highway design but also plays a crucial role in transport planning and policy-making. Make sure to memorize the classifications, IRC codes, and traffic thresholds to score well in competitive exams.