A $7.5$ m wide two-lane road on a plain terrain is to be laid along a horizontal curve of radius $510$ m. For a design speed of $100$ kmph, super elevation is provided as per $\text{IRC:}73-1980$. Consider acceleration due to gravity as $9.81 m/s^2$. The level difference between the inner and outer edges of the road (in m, upto three decimal places is ________