Highway Engineering
For design, that length of transition curve should be taken which is

smaller of (A) and (B)
based on rate of change of super elevation
higher of (A) and (B)
based on allowable rate of change of centrifugal acceleration

ANSWER DOWNLOAD EXAMIANS APP

Highway Engineering
A traffic rotary is justified where

when traffic volume is more than 5000 vehicles per hour
number of intersecting roads is between 4 and 7
when traffic volume is less than 500 vehicles per hour
space is limited and costly

ANSWER DOWNLOAD EXAMIANS APP