This is a very simple thing to do.
Start by selecting 'Begin special build mode' in the 'Landscaping'
menu of the Beast
Trainer. Then wait for the 'Begin building' message in the message
bar and build a 'double-wide' path that you want to make into the
road. After that, select 'Execute build roads' from the 'Landscaping'
Game Modifier also has the option to make a 'double-wide' path
into a road. This option is under the "Scenery"
tab in the utility.