Parliament Question: Guidelines for Geometric Design in Hilly Terrains

**Executive Summary** This document summarizes the answer provided by the Minister of Road Transport and Highways to Unstarred Question No. 2140 in the Lok Sabha, answered on February 12, 2026, regarding guidelines for geometric design in hilly terrains. It addresses the salient features and implementation status of relevant IRC guidelines, construction rules enforced for hairpin bends, and decisions regarding speed limits on National Highways in hilly areas. A circular was also issued on November 7th, 2025 to address concerns regarding construction of National Highways in Hilly Regions. **Key Points / Main Content** * **General Guidelines:** * National Highway projects are executed in accordance with Contract/Concession Agreements formulated as per Indian Roads Congress (IRC) Manuals/Guidelines. * Applicable IRC guidelines for hilly terrain projects primarily include IRC:52 "Guidelines for the Alignment Survey and Geometric Design of Hill Roads" and IRC: SP:48 "Hill Road Manual". * **Geometric Design Parameters (IRC:52):** * Geometric design parameters (design speed, horizontal curve radii, super-elevation, hairpin bends, vertical gradient, etc.) are provided in conformity with IRC:52. * IRC:52-2019 details hairpin bends with 15–30 meter curve radii, ruling gradients up to 7%, and superelevation. * **Construction and Safety (IRC: SP:48):** * Hill cuttings, erosion control (including bio-engineering), safety & traffic control, and ecological & environmental measures are in line with IRC: SP:48. * NHAI construction rules enforced for hairpin bends in Himachal Pradesh incorporate erosion control measures under IRC: SP:48-2023, avoidance of 90-degree hill cuttings and integration with Green National Highways Corridor Project standards. * IRC: SP:48 ensures safe traffic reversal, enhances sustainability, reduces accidents, and preserves mountainous ecosystems. * **Speed Limits:** * Decisions regarding speed limits on National Highways in hilly areas specify ruling design speeds of 40-60 km/h in steep terrains with variations for public transport safety under Ministry SOPs. * **Circular:** * The Ministry of Road Transport & Highways issued a circular on November 7, 2025, for systematic remedial measures to address concerns regarding construction of National Highways in Hilly Regions. **Impact Analysis** **Stakeholder: National Highway Authorities/Engineers** * **Impact:** Required to implement projects according to IRC:52, IRC: SP:48, Contract/Concession Agreements and the circular dated November 7th, 2025. * **Action Required:** Adhere to the IRC guidelines for geometric design, construction rules, erosion control measures, safety standards, and environmental preservation. **Stakeholder: Government (Ministry of Road Transport and Highways)** * **Impact:** Responsible for ensuring adherence to regulations and updating rules to enhance sustainability and accident reduction. * **Action Required:** Monitor implementation of guidelines, address concerns regarding construction in hilly regions, and update rules as needed. **Stakeholder: Public/Commuters** * **Impact:** Affected by the safety, efficiency, and sustainability of National Highways in hilly regions. * **Action Required:** Benefit from improved road safety, reduced accidents, and preservation of mountainous ecosystems. **Stakeholder: Himachal Pradesh (and other States with Hilly Terrains)** * **Impact:** Affected by the construction and maintenance of National Highways within their territory. * **Action Required:** Implement the guidelines to enhance sustainability and accident reduction in the state.

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