Why topologize model?There are three main reasons.
Sufficient topology lines can insure roads be deformed correctly.
UVW Mapping need sufficient vertices and edges.
Watching a scene more fluently ,help to improve rendering speed.
The road in this file is an editable polygon converted from a spline shape ,the layout of vertices is not regular because original dwg file is not good,so CutByAgl is used a lot to cut road.If the number of vertices on bothside of road is same ,ConnectVerts is better.
Lay out topology lines for road
In the Step,MoveVerts is used to conform the road to the terrain because of lacking level data,then SMRoad tools to smooth road ,at last conform faces covered by road to it.In the basic version ,SmoothRoad (which has a user interface) can be substitute for SMRoad tools,you can watch last video to see how to use it.
Smooth Road and conform it to terrain
Connect the road to terrain
In this Step, the road is attached to terrain,the holes are capped ,then StitchVerts is used to topologize new polygon.StitchVerts is unavailable in Lite version ,you can use AdvConnectVerts to substitute for it.
Connect Road to Terrain
If you are using basic version of TerrainAxe,you can watch the below video to complete tutorial.