EngineeringBhanu · Class 4-5
Surakshit sadak ka design: ginti, lane aur underpass
Ek tez sadak (expressway) par gaadiyaan bina ruke chalti hain. Gaon ka kisan apne khet tak tractor lekar kaise jaaye?
Socho pehle… phir dekho jawab
Sadak ke neeche se! Naye niyam kehte hain ki jahan harvester aur bhare hue tractor chalte hain, wahan 4.5 metre ooncha underpass ban sakta hai — taaki woh aaraam se nikal jaayein.
Engineer sadak design karne se pehle gaadiyaan ginte hain. Truck, bus, scooter — sabko 'car ke barabar' mein badalte hain. Ise PCU (passenger car unit) kehte hain. Jitne zyada PCU, utni zyada lane: kam traffic par 4 lane, zyada par 6 lane.
Cause-effect: tez sadak par chauraha ho toh gaadiyon ke raaste aapas mein katte hain aur takkar ka khatra rehta hai. Isliye naye expressway par koi chauraha nahi hoga — sadak par aana-jaana sirf dhalaan (ramp) se, aur paar karna underpass se. Toll par bhi rukna nahi: bina barrier ke toll katega.
Aur samajhdaari: kabhi sadak 4 lane ki hoti hai par us par pul 6 lane ke banate hain. Kyun? Traffic badhega toh sadak chaudi karna aasaan hai, pul ko chauda karna bahut mushkil.
Ghar pe try karo
Gatte ya chart paper par ek expressway banao. Ek khilona tractor ki oonchai naapo aur do kitaabon ke beech usse ooncha underpass banao, taaki tractor aaraam se nikle. Sadak par chadhne ke liye ek jhuka hua gatta (ramp) lagao.
Wow!
4.5 metre ooncha underpass — lagbhag teen bade logon jitna, ek ke upar ek khade hon toh!
Mummy-Papa ke liye
Aaj bachche ke saath gatte ka expressway aur underpass banaiye, aur bataiye ki tez sadak paar karne ka safe tareeka underpass ya pul hai.
3 sawaal
- PCU kya hai?
Jawab dekho
Truck-bus ko car ke barabar ginne ka tareeka. PCU = passenger car unit; sab gaadiyon ko car ke barabar mein ginte hain.
- Naye expressway par aana-jaana kaise hoga?
Jawab dekho
Sirf ramp (dhalaan) se. Expressway par chauraha nahi, sirf designed ramp.
- 4 lane sadak par 6 lane ka pul kyun?
Jawab dekho
Baad mein pul chauda karna bahut mushkil hai. Sadak chaudi karna aasaan, pul chauda karna mushkil.
NCERT se jodo: NCERT Class 4 EVS (Looking Around) — school tak ka raasta: sadak aur pul