Commencing with reasons the first and foremost reason is, railways are cheaper and convenient. To explicate it, passengers travelling to far distances mostly prefer railways over roadways because they are affordable and seats are much comfortable than buses. Interestingly railways can carry 500-1000 passengers at a single time. In addition, poor and middle class people generally travel by train which is quite affordable than buses and cars. Hence, railways have been proven boon for mankind.
Secondly rail transport declines traffic and pollution to large extent as both these issues are major concern nowadays. By allocating funds on railways will decrease this problem by 30 to 40%. For instance 3 to 4 hours of traffic is just a normal thing in Big Cities such as Delhi and Mumbai, if person have to reach 30 km away from his home. Additionally, government has introduced eco friendly trains which runs on electricity and cover large distances is a short period of time. So , they not only solve problem if traffic but also decrease pollution to large extent.
In recapitulation, investing money on railways will be fruitful as it will solve major concerns of human such as traffic and pollution.