Been trying to draw up a survey using tunnel. I have linked the walls to the centreline and still the order of the overlying passages is in the wrong order. How can this be corrected?

Did you make sure you clicked 'Update Z Order' before updating the areas? This allows Tunnel to calculate which areas should appear on top of others.

Failing that, are the areas which are not appearing in the correct order connected to centrelines through the overlapping passages? If not then sometimes the overlap comes out wrong, but you can set a vertical offset using connective lines to force one area on top of another. I'd have to dig out the details to tell you exactly how though.

I have connected all the stations to the corresponding walls. If you dont mind digging out the details it would be useful. Failing that i could email you the file if it makes it easier.

Cheers

OK, found it on this miscellaneous things that are not covered elsewhere in the help page!
http://www.freesteel.co.uk/wiki/index.php/A_walk_through_tunnel_-_Additional_topics

Basically you draw a connective line between a centreline node in a nearby passage and a node on the wall of your passage which you want to force to appear above or below the level of that connected centreline node from the nearby passage. Then assign the area signal type zsetrelative to that connective line, and enter the height in metres +ve or -ve that you want to offset the height of the passage without it's own centreline.

If you still can't fix it from that, send me a PM for my email address (if you don't already have it) and email me your Tunnel project file and I will take a look.