India’s 50,000-km high-speed road plan: What new highway design rules say, Pg15

Key Highlights:

• The National Highways Authority of India (NHAI) has issued detailed guidelines for the design and construction of high-speed corridors, also known as access-controlled national highways or expressways.
• These new rules aim to standardize Detailed Project Reports (DPRs) and ensure uniformity in construction.
• India targets developing 50,000 km of high-speed corridors by 2036-37 under Vision 2047.
• As of December 2023, the total length of high-speed corridors stood at 3,052 km.
• The guidelines mandate provisions for a Multi-lane Free Flow (MLFF) tolling system and a 1-meter high Reinforced Cement Concrete (RCC) boundary wall along the entire Right of Way (ROW).

Detailed Insights:

• The new guidelines address previous inconsistencies in standards used by consultants for preparing DPRs for these corridors.
• Traffic assessment for projects must now include existing, generated, induced, and diverted traffic, validated by sources like GST portals and toll transactions.
• Lane configurations are determined by traffic volume, with specific requirements for 4-lane and 6-lane highways based on Passenger Car Unit (PCU) thresholds.
• Strict access control is mandated, prohibiting at-grade intersections and requiring access only through properly designed ramps at specific locations.
• Safety features include specific signage placement (overhead gantries 5 km and 2 km before exits, cantilever gantries 1 km and 500 meters before exits) and standardized lane markings.
• Underpass heights of 4.50 meters are recommended in areas with frequent heavy agricultural machinery operations.
• Service roads with drain-cum-footpaths are to be provided in built-up and urban sections on both sides.
• Drip irrigation for median plantations and tree plantation are to be integrated into the project design at the DPR stage.

Key Concepts Involved:

• Access-controlled national highways/expressways: Roads designed for high-speed traffic with regulated entry and exit points, no at-grade intersections, and separated opposing traffic flows.
• Passenger Car Unit (PCU): A metric used in transportation engineering to quantify the impact of different vehicle types on traffic flow, converting them to an equivalent number of passenger cars.
• Multi-lane Free Flow (MLFF): A barrier-less electronic tolling system that allows vehicles to pass through toll points without stopping or slowing down significantly.
• Right of Way (ROW): The total width of land legally acquired or owned by the government for the construction, operation, maintenance, and future expansion of a highway.