好，我用规则来补充我2L的回答
1 Note that these pathways may extend beyond the borders of the 5 by 9 card pattern indicated in the illustration.
这个就要说道翻译的问题了，原文的extend beyond明明是说可以超过5*9的范围，到了中文翻译版变成了：“提示：道路可以扩展到下图所示9张牌主线路为中心的5张牌范围内（即长度不超出起始牌到目标牌，宽度不超出上下目标牌）。”
2 A path card must always be put next to a path card that is already on the table. The paths on all sides of the card must fit those already in play, and a path card may never be played crosswise.
规则里只有这三条 必须和原有的道路卡相邻，每条边都必须和已有的吻合，道路卡不能横放
所以“所有坑道应该是从起点渐渐接近终点的”的出处还是未知。
欢迎继续讨论
