Abstract: A shape of a boundary line between a forward view in a forward field of vision of a driver and a vehicle structural part that blocks a lower end of the forward view, i.e., the shape of a so-called visible edge of a vehicle hood, a shape of a visible edge of a vehicle instrument panel, or a shape of a top edge of a ceramic line formed at a windshield glass is made to be a curve. The curve may be expressed by hyperbolic function y2=Ax2+2Bx+C, where x is a depression angle, y is an azimuth angle, A is a constant expressed by a sum of a ratio of a distance between a viewpoint height and a roll axis with respect to the viewpoint height and a reciprocal of a product of a roll rate and the viewpoint height, B is a constant expressed by a reciprocal of the roll rate, and C is a constant expressed by the constant A, the constant B and a depression angle of a sight-line direction of a driver.

Abstract: A shape of a visible edge of a vehicle hood, a shape of a visible edge of a vehicle instrument panel, or a shape of a top edge of a ceramic line formed at a windshield glass is made to be a curve expressed by hyperbolic function y2=Ax2+2Bx+C, where x is a depression angle, y is an azimuth angle, A is a constant expressed by a sum of a ratio of a distance between a viewpoint height and a roll axis with respect to the viewpoint height and a reciprocal of a product of a roll rate and the viewpoint height, B is a constant expressed by a reciprocal of the roll rate, and C is a constant expressed by the constant A, the constant B and a depression angle of a sight-line direction of a driver.