The long tunnel that connects Khopoli to Lonavala will be built by the Maharashtra State Road Development Corporation (MSRDC).
The expressway famously known as the Old Mumbai Pune Highway is a part of the corporation's plan to expand the NH-4 and the expressway.
India's longest tunnel, Rohtang Tunnel, that is under construction on Leh Manali Highway will be completed by the year 2014. The work for tunnel that is to be build in Maharashtra is expected to begin by the end of year 2012 and is expected to make its way through mountains so as to emerge at the Singhagad Educational Institute situated in Lonavala.
"We will add two lanes to the six-lane Mumbai-Pune Express-way and two new lanes to the four-lane old highway," said MSRDC vice chairman and managing director, Bipin Shrimali.
At a point near Khandala, both expressway and NH-4 come together to form a common road. The roads get jammed in case of landslides or accidents that are frequent during the monsoon.
The MSRDC believes that the tunnel will ease the traffic problem for motorists.