Follow black and white line simultaneously
It depends a bit on your precise requirements. Currently you are following the black line (meaning sensing black in the middle and white on the sides). Instead you could follow the border of that line. To do this you would have to control the motors in a way, so that in at the middle of the sensors there is a high contrast (black at the right, white at the left, or vice versa). It will not follow the exact same path as before, but a bit to the side.