Al Johnson wrote:
The Perfect Engineering card allows you to "lay up to 5 track segments in a single link." The rulebook states under the purple diamond on page 7 that; "This does not count as an action." I assume then that this could be used as an "additional action" during any of the three rounds. Which means in one round you could lay as many as 9 tiles if you could afford them. Is this correct?
No. It means that instead of building up to four tiles in one action, you can build up to five tiles in one action (once per card per turn, if you happen to have both PE cards).
Also, you still pay for every tile normally, including the fifth one. (An exception is when you play Government Land Grant, in which case you could combine the two cards and get up to five free tiles if they are all on open terrain; however, GLG only makes tiles on open terrain free, it doesn't raise the tile placement limits either)