Theme: Track, conductor path
How can I change the width of a track?
Actually there are two questions inside:
How can I change an existing track?
Select the track in question and press keyboard key [e] for edit. The dialog "Change tracks" opens and allows adaption, for example the track width. If you only want to adapt a single segment of a track you just might double click it (M11)
How can I change the presettings for a future track?
If you already are in the "Draw track" mode please press keyboard key [o] for options. In the flashing dialog you can set the details of the tracks to come.
In the schematic you can already define the future track width of a certain signal or a class of signals e.g. GND = 40 mils. For doing so, please double click (M11) the green signal track in the schematic. Look at the bottom of the dialog and set the track width for this signal which is about to come in the layout.
You can also set the width for future tracks for signals without such a width definition: Goto menu "Settings" point "Settings (project)". Here you can set the standard track width and also the minimum track with for the design rule check (DRC).