A road in a hilly terrain is to be laid at a gradient of $4.5 \% .$ A horizontal curve of radius $100 \mathrm{~m}$ is laid at a location on this road. Gradient needs to be eased due to combination of curved horizontal and vertical profiles of the road. As per IRC, the compensated gradient (in \%, round off to one decimal place), is
A road in a hilly terrain is to be laid at a gradient of $4.5 \% .$ A horizontal curve of radius $100 \mathrm{~m}$ is laid at a location on this road. Gradient needs to be eased due to combination of curved horizontal and vertical profiles of the road. As per IRC, the compensated gradient (in \%, round off to one decimal place), is