In visitor 3 choose only roads, then click the Ground/Sea button on the main menu to switch the mapview into blue. Unselect Show Grid also. Now choose Project → Export map as image.

Run the EMF image through the usual course and get to Photoshop. Get rid of blue edge (tutorial in our wiki somewhere heh).

Select → Color Range. Then click anywhere in the blue, press OK and now your blue areas are selected, now do Select → Inverse, now your roads are selected. Use Select → Modify → Expand, put in like 1-2 pixels so you make the road bit wider.

Please note that the expand pixel amount depends on your satellite texture resolution, if the resolution is low, then even two pixel expanding means the texture-road will be very wide, maybe even twice as wide as the real road object. You need to experiment with this if you're running lower resolution satellite texture (ie more pixels per meter).

Use paint bucket tool, choose Edit → Fill to fill the selection or layer with color.

Double click roads layer to get into Layer Style blending options. In the blend If: part, choose blue from drop down and adjust the This Layer: part into near 0 to make the blue disappear.

Now create another layer under the roads, then just click roads and Merge Down, now your roads are in the merged layer and no blending options needed.

When you paste the roads layer into your satellite PSB file, if its pure EMPTY without color besides the roads, then Photoshop paste somehow aligns the content, you can fix this by placing single pixel on the lower left and lower right corners of the image, this way it cannot move as it has content on each edge. Strange but that is how it works.