A light guide body has a first light guide part disposed in front of a light source, a second light guide part extending from a front surface side of the first light guide part toward at least one lateral side of the first light guide part, a plurality of third light guide parts branching and extending from a midway portion of the second light guide part, an incidence part located on a back surface side of the first light guide part, and a first emission part located on a tip side of the plurality of third light guide parts, the second light guide part has a shape in which a cross-sectional area gradually decreases toward the tip side, and the plurality of third light guide parts are arranged next to each other in an extension direction of the second light guide part.

A running light for a vehicle includes at least one light source, a number of first optical waveguides on a first side, a number of second optical waveguides on a second side opposite the first side. One of the first waveguides emits light from the at least one light source in both the main beam direction, which runs along a main axis orthogonal to a secondary axis connecting the first side and second side, as well as in a first area toward the number of second waveguides. The second waveguide emits the light from the at least one light source in both the main beam direction and in a second area toward the number of first waveguides.