At a curved path of the road, the road bed is raised a little on the side away from the centre of the curved path. The slope of the road bed is given by
tan q = $\left(\dfrac{r}{gv^2}\right)$
tan q = $\left(\dfrac{rg}{v^2}\right)$
tan q = $\left(\dfrac{v^2g}{r}\right)$
tan q = $\left(\dfrac{v^2}{rg}\right)$