| 摘要 |
<p>A road 10 includes two outer lanes 12 and 14 and a central lane 16. Traffic flowing along the outer lane 12 always flows in the direction of arrow 18 and traffic flowing in the other outer lane 14 always flows in the opposite direction 20. The traffic flowing in the central lane 15 selectively flows in one of the directions 18 or 20. When traffic in the central lane flows in the direction of arrow 18 alternative road markers 22 located between the mains 12 and 16 emit a green light in the direction 20. Alternate road markers 24 located between the lanes 14 and 16 emit a red light in the direction of arrow 20. When traffic in the central lane is to flow in the opposite direction 20 the road markers 22 and 24 are switched off and alternate road markers 26 between the lanes 18 and 16 emit a red light in both directions and alternate road markers 28 between the lanes 14 and 16 emit a green light in the direction of arrow 18. <IMAGE></p> |
