A resource becomes more valuable as it becomes more scarce.
I believe the answer is: Heroin
Heroin is known for its euphoric effect, which make it a really popular recreational drugs even though its usage is heavily regulated. The increase in heart rate happen because heroin stimulate the user's central nervous system to mimic its function during high-adrenaline/exciting situations.
Explanation:
People from Madhes/Terai will have easy reach to capital which may help to reduce socio-political issues with Kathmandu too. 2)This Fast track also brings Birjung, Nepali trade point to India, closer to the Chinese border. ... 4)Kathmandu Terai/Madhesh Fast Track is strategic road development for Nepal