A track support rail for supporting a track assembly of a machine, the track assembly being slidably movable over the track support rail, the track support rail comprising: a body, the body including a first body end, a second body end, a crown portion, and an upper support surface, the body extending along a longitudinal axis between the first body end and the second body end, the crown portion disposed between the first body end and the second body end along the longitudinal axis, and the upper support surface extending along the longitudinal axis between the first body end and the second body end; wherein the upper support surface includes a first curved segment and a second curved segment, the first curved segment having a first curved shape and extending from the first body end toward the crown portion of the body, the second curved segment having a second curved shape and extending from the second body end toward the crown portion of the body, the first curved shape being different from the second curved shape, wherein the first curved segment includes a first rounded corner, the second curved segment includes a second rounded corner, the first rounded corner has a first corner shape, and the second rounded corner has a second corner shape, the second corner shape being different from the first corner shape, and wherein the upper support surface includes a crown segment disposed in overlying relationship with the crown portion of the body, and wherein the first rounded corner has a first radius of longitudinal curvature (R1L) in a longitudinal plane, the second rounded corner has a second radius of longitudinal curvature (R2L) in the longitudinal plane, and the crown segment has a third radius of longitudinal curvature (R3L) in the longitudinal plane, the longitudinal plane extending through a lateral midpoint of the body taken along a transverse axis, the transverse axis being perpendicular to the longitudinal axis, the longitudinal plane being defined by the longitudinal axis and a vertical axis, the vertical axis being perpendicular to both the longitudinal axis and the transverse axis, and the third radius of longitudinal curvature (R3L) being different from both the first radius of longitudinal curvature (R1L) and the second radius of longitudinal curvature (R2L). a body, the body including a first body end, a second body end, a crown portion, and an upper support surface, the body extending along a longitudinal axis between the first body end and the second body end, the crown portion disposed between the first body end and the second body end along the longitudinal axis, and the upper support surface extending along the longitudinal axis between the first body end and the second body end; wherein the upper support surface includes a first curved segment and a second curved segment, the first curved segment having a first curved shape and extending from the first body end toward the crown portion of the body, the second curved segment having a second curved shape and extending from the second body end toward the crown portion of the body, the first curved shape being different from the second curved shape, wherein the first curved segment includes a first rounded corner, the second curved segment includes a second rounded corner, the first rounded corner has a first corner shape, and the second rounded corner has a second corner shape, the second corner shape being different from the first corner shape, and wherein the upper support surface includes a crown segment disposed in overlying relationship with the crown portion of the body, and wherein the first rounded corner has a first radius of longitudinal curvature (R1L) in a longitudinal plane, the second rounded corner has a second radius of longitudinal curvature (R2L) in the longitudinal plane, and the crown segment has a third radius of longitudinal curvature (R3L) in the longitudinal plane, the longitudinal plane extending through a lateral midpoint of the body taken along a transverse axis, the transverse axis being perpendicular to the longitudinal axis, the longitudinal plane being defined by the longitudinal axis and a vertical axis, the vertical axis being perpendicular to both the longitudinal axis and the transverse axis, and the third radius of longitudinal curvature (R3L) being different from both the first radius of longitudinal curvature (R1L) and the second radius of longitudinal curvature (R2L).