Gt bro thats exactly the kind of answer i was looking for. I am trying to prepare a techinical report redarging this matter too and if possible direct it to the concerned authorities in the future. And thanks a lot for your valuable input.

this is another input by one of my friend in Environmetal field in Nepal
"I think its not about affordability, its more about management and approach. I think government has no plans at all regarding this particular issue, though overall government have policy for whole Nepal to make defecation free. I think there is also necessity to raise this issue to the government authorities. I think it is responsibility of Government to make proper plans,then monitor and coordinate with bus operating companies to provide good facility of rest areas along major highways. I think other issue is also about the condition of toilet facilities where bus operator stops during trip. I think there should be proper monitoring by government on bus operators and this hotels where they stop in highways regarding both rest facilities and food. Usually I think bus operators are also to blame who just grab monetary benefit from hotels in highways and do not provide good service to passengers. Moreover I think it is due to syndicate system of bus companies and I think there should be open market competition with proper monitoring.
Regarding you last part, announcing no defecation area I am confused, are you asking about announcing village and districts no defecation area or are you asking about some signboards in some area of highway with no defecation area written. If you are asking about announcing village and districts, no defecation area, then I think it is little different issue with those of highway."

Friends hope to see more of your valuable inputs