I think a joint venture company called Nepal Infrastructure Development Company, headed by some industralists and private sectors are constructing this Kathmandu-Hetauda Tunnel way. I believe they are constructing that project as a "Turnpike." Kathmandu-Terai is headed by GoN as a freeway which will eventually link Kathmandu valley with proposed Nijgadh international airport in Nijgadh, Bara. These two projects will serve different purpose and if constructed as planned, will definetely ease conjested trafficks entering and leaving valley. I have been doing research on current and proposed projects, which if constructed as planned, will definetely uplift Nepal to developing countries of Asian standards. Some of these are:
1) Multipurpose & reservoir styled Upper Karnali Hydropower Project
2) Arun 3 (Required energy should be supplied to eastern region of Nepal as per demand.)
3) west Seti storage Hydropower project (750 megawatt) 
4) Budigandaki storage Hydropower Project (600 megawatt)
5) Tamakoshi 3 Hydropower Project (600 megawatt)
6) Midhill Highway linking east west Nepal
7) Kathmandu-Terai Fast Track 
8) Kathmandu-Hetauda Tunnel Way
9) North-south corridors (linking Tibet to India via Nepal)
10) Chemical fertilizer plants in various part of Nepal
11) Developing Lumbini as makka-madina/vatican of Buddhists
12) Upgrading Pokhra and Bhairawa airport to regional international airport.
13) Developing at least 5 Dhulikhel Community Hospital style healthcare facility in every zone of Nepal
14) Merging government schools and colleges, upgrading them with necessary facilities and human resource.
15) Developing Agro based industries like meat/dairy/herbs/spice processing plants in each and every districts of Nepal according to their specialties. Ex. eastern (Ilam) is known for tea/herb whereas farwestern regions(Doti) for herbs (Yarshagumba). If government can develop processing plants in public private people partnership (4P) model, no kidding these plants will create employment for 1000s. Deprived won't have to go to India to become bahadur and khancha.
16) Government subsidy to people who want to buy modern agruculture equipments like tractors, trucks, harvestors etc.
17) Construction of Sikta, Babai, Naumure irrigration projects on time so that 1000s hectar fertile Teari land can be irrigated. Doing that 3 cultivations can be easily done throughout the year. (Now its hardly twice)
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Guys add more