"[I]ncrease in the number of lanes appear to increase traffic-related fatalities. Increased lane widths appear to be associated with increased fatalities. Increases in outside shoulder appear to be associated with a decrease in accidents. No statistical association with changes in safety is found for median widths, inside shoulder widths, and horizontal and vertical curvature." "[I]ncrease in the number of lanes appear to increase traffic-related fatalities. Increased lane widths appear to be associated with increased fatalities. Increases in outside shoulder appear to be associated with a decrease in accidents. No statistical association with changes in safety is found for median widths, inside shoulder widths, and horizontal and vertical curvature."