Needle's Eye Tunnel is Feasible: Study by Deere and Gross

Deere and Ault Consultants completed a feasibility study of reopening Needle's Eye Tunnel that states that the tunnel can be repaired for less that $500,000.  

Their conclusion was:

"The Needle’s Eye Tunnel can be safely repaired for public access using shotcrete and rock bolts."

Don W Deere, PE & Christoph Goss, PhD, PE

You can read the full study below: