Different track types on mega europe?

[Manstie]

Just trying out a second map and on mega europe there are grey tiles bordered with black as well as grey tiles with trains on them, what do they mean?

[Darinthal]

Grey Tiles with trains are Locomotive tracks. You need a locomotive to use them (The Rainbow Train Cards), You need one for each space with the train symbol on them.

The Tracks with surrounds are tunnels (Both Grey and Colours). Everytime you take those tracks you have to spend up to 3 more of the coloured/rainbow cards to take the track. When you take the track the game puts 3 more cards up. They tell you how many extra cards you have to spend. For the Grey tracks you have to spend extra cards the same colour you use or rainbow cards. If you use only rainbow cards to take the track then you can only use rainbow cards as extra cards if it requires extra cards.
Failure to provide the extra cards fails to take the track and you get your cards back and forfeit your turn.