National Highway Authority (NHA), during past one year, has successfully attracted private sector investment with projects worth over Rs. 144 billion surpassing the average annual Foreign Direct Investment (FDI) in Pakistan. Besides other benefits, the expected revenue earnings from these projects would be over Rs. 391 billion, an official of NHA told APP here on Friday. He said the modern concept of infrastructure development, Public Private Partnership (PPP) has become a popular mode of road construction also known as Build-Operate-Transfer (BOT) model in which the private sector builds a project and operate a facility for an agreed period of time ranging from 20 to 30 years. The private party bears the responsibility of design, construction, operation and maintenance of the project and in return the party is authorized to receive toll/other revenue for a certain period.