Continuous Road Traffic

I have created a small project for the purpose of learning about route building. There is a stretch of road (with traffic) along side the rails for a length of four miles, at least. The issue I am having is that the traffic driving on the road is not continuous. The traffic breaks at the spots on the road that have the red triangles at the joint. I'll be driving along and suddenly the tractor-trailer beside me disappears.
Is there some procedure to link all four miles of the road so that traffic is continuous along the whole stretch?
for your help on this.
Is there some procedure to link all four miles of the road so that traffic is continuous along the whole stretch?
