Hello. Thanks for mapping on this highway project.
A few remarks.
Please read the instructions. The goal is mapping roads accessible for cars.
This means that you have to measure the width of the trace.

How to measure the width of a trace In Ideditor:
Command Ctr+shift+M  shows the  measuring dimensions tab.
After that command, select add line.
Zoom in very far (20 - 25 mtr) so that you have a good view on the shoulders of a road.
Then draw a line between the shoulders.
You can read the value in the measurement tab. (select Metric value)
<2 mtr tag it Path
> 2 mtr tag it unclassified, residential or track depending on the situation. 
 Delete the line after measuring.
Best regards and keep mapping