The prime minister and Gandhi, who are in Jaipur to attend a Congress brainstorming session, inaugurated the Ghat Ki Guni tunnel in the afternoon.
The function was beamed live on 13 large screens put up at various locations in the city, said an official of the urban development and housing department.
Chief Minister Ashok Gehlot and other ministers and party leaders participated in the function.
The tunnel connects Jawahar Nagar bypass and Agra Road near Goner junction. A sum of Rs.150 crore was spent on the project, the offcial said.
The tunnel will have controlled traffic movement, sensors for control of air pollution, display boards and cameras for checking vehicles' speed, the official said.