The proposed high-speed railway corridor between Delhi and Varanasi has hit a roadblock with the Railway Board rejecting the feasibility report on the project citing multiple curves along the route which will not be suitable for a bullet train to run at 350 kmph, sources said.

The sources indicated that the decision was taken at a meeting held by Railway Board Secretary R N Singh last week to review the bullet train project.

The feasibility study report was presented by the National High Speed Rail Corporation Limited (NHSRCL).

The feasibility report proposed the corridor be built along the National Highway-2. It said this will help in the acquisition of land at cheaper rates and reducing the cost of construction.

However, the technical issue which led to the outright rejection of the proposal was that NH-2 had curved sections at many places between Delhi and Varanasi, which would make it highly dangerous for a train to run at 350 kilometre per hour, a source present in the meeting said.

"To run a bullet train at a speed of 350 kmph, the track of high-speed corridor should be straight," the source said.

While NHSRCL is keen on beginning the work on the project, the Railway Board is wary, especially considering the delays and roadblocks in the ongoing bullet train project between Mumbai and Ahmedabad.

Due to the delays, sources said, the estimated cost of the Mumbai-Ahmedabad project is set to reach Rs 1.50 lakh crore. Officials said around Rs 200 crore is being spent per kilometer to build the high-speed corridor.

The Railway Board has suggested that for now, the focus should be on running only semi-high speed Vade Bharat trains at a speed of 160- 200 kmph. Officials said around 400 such trains will be available over the next three years and can be used on different routes.