Work on a 42-km bypass linking the Kerala capital with Tamil Nadu is set to start -- after a wait of 40 long years, Congress MP Shashi Tharoor announced on Monday.A central minister will lay the foundation stone for the project on Tuesday. One part of the stretch will be ready in two years, and the whole road will take four years to be operational.The road would ease the traffic flow into Thiruvananthapuram."I had to pursue this with two central governments (UPA II and the present NDA government). It took me six years to see this project," the Thiruvananthapuram MP told the media here."The land for this project was identified and was marked for acquisition more than 35 years back. "It was from 2009 that I started to pursue the project... The first phase would be over in two years and the second phase in four years," he said.