Manual for Survey, Investigation and Preparation of Road Projects (Second Revision)
2001 Edition

The IRC SP 19 manual recommends starting with a traverse survey along the probable final center line, utilizing secondary traverses where necessary. In hilly terrain, a trace cut of about 1.0 to 1.2 meters width may be made. Distance measurements should be performed using EDM or total stations, maintaining an accuracy of at least 1:10,000. Transit stations must be marked with stakes spaced according to terrain and alignment complexity. Physical features such as buildings and utilities are located by offsets from the traverse line. Levelling is done through fly levels at 50-meter intervals, with cross-sections taken at intervals depending on the terrain type. Benchmarks connected to the GTS datum are established every 250 to 500 meters. During the survey, data related to traffic, soil, and drainage are also collected. Maps and plans including contour lines (1-3 m intervals) are prepared with scales adapted to the terrain, facilitating accurate final alignment selection.

IRC SP 19 outlines comprehensive soil and material investigation procedures aimed at determining essential engineering parameters such as shear strength, unit weight, moisture content, and consolidation characteristics, particularly for the design of high embankments. It refers to specialized guidelines in IRC Special Reports 13 and 14 and the Ministry of Road Transport & Highways circulars, emphasizing detailed laboratory tests—including sieve analysis, Atterberg limits, density, and California Bearing Ratio—and field tests to assess soil behavior. The standard also recommends employing software tools like HED v1.0 for slope stability analysis, incorporating seismic considerations. Special investigations are advised for challenging terrains such as hilly or erosion-prone areas to ensure embankment safety and durability.

IRC SP 19 specifies three principal methods for estimating traffic growth rates: (1) Time trend analysis using classified volume counts through linear regression, effective when the coefficient of determination (R²) is 0.75 or higher; (2) Systematic forecasting based on zonal origin-destination data incorporating population, real income growth, and elasticity of transport demand; and (3) a simplified approach following Asian Development Bank guidelines, which projects traffic growth using annual population and income increases within the Road Influence Area, applying elasticity coefficients. Passenger vehicle growth rates vary over successive five-year periods with different elasticity values assigned to vehicle categories. Freight traffic growth is estimated from weighted averages of economic sectors derived from state domestic product data, adjusted iteratively for regional consistency.

The environmental impact assessment (EIA) process prescribed in IRC SP 19 involves initial screening and conducting an Initial Environmental Examination (IEE) to identify potential positive and negative effects. Baseline environmental data collection forms the foundation for this analysis. Environmental design integrates socio-economic studies and compliance with regulations including the Environmental Protection Act, Wildlife Protection Act, Forest Conservation Act, and Coastal Zone Regulations. Preparation of a Resettlement and Rehabilitation Action Plan may be required. Mitigation strategies are outlined in an Environmental Management Action Plan (EMAP) focusing on cost-effective measures to reduce adverse impacts and enhance benefits. Some improvement works with minimal land acquisition along existing roads might be exempted from full environmental clearance. The process aligns with MOEF guidelines and IRC:104.

According to IRC SP 19, the Detailed Project Report (DPR) must be comprehensive, clearly structured, and divided into three parts, with the core being the Project Report. Essential components include an Executive Summary outlining key highlights, an Introduction with project background, a Socio-economic Profile, Traffic Surveys and Forecasts, Engineering Surveys and Investigations, Pavement Studies, and applicable Design Standards. The report should also cover Drainage and Cross-Drainage Structures, Environmental and Social considerations including resettlement, Materials and Equipment requirements, detailed Rates and Cost Estimates, Economic and Financial Analyses, Construction Constraints, and Scheduling. The DPR must include design calculations and supporting data, presented clearly, often in tabular formats, and adhere to checklists provided in the appendices to ensure completeness and facilitate administrative and technical approvals.