This is probably rather late for you, but you can create working freeway traffic by using SBuilder. Draw your roads - I use GP roads I've created myself - in ADE and compile. Make a note of the number of vertices you used to create the GP Road. Launch FSX and position the Microlight over the start of the road in Slew mode.
Launch SBuilder and create a new Project, taking care to set the BGL Compile Folder. Select View .. Show Aircraft. Effectively you have now set the middle of the screen to the lat/Lon of your aircraft.
You may want to zoom in at this point. You could go through the pain of taking a screen shot via Google Earth or Google Maps and load that as a map, but not really necessary. It just helps with scale.
In SB use the Line Tool to create a Vector line with as many points as you used vertices in ADE. When done, with the whole line selected - by default it changes from Blue to Green- right click and select from the general tab, the width in Meters. You can choose to have the road width change from end to end too. In the Vector Lines Tab set the number of lanes and the direction of flow as F(orward). Now you can switch between FSX in Slew mode and SB and even if you wish, ADE in connected mode. Slewing the aircraft to each point / Vertex on your road and going back to SB to move the point onto the cross will allow you to create a copy of the ADE road in SB. (Warning: I think you may need FSUIPC free version to link SB and FSX.
If you missed out some points, as I did on the first go, you can select the line, make sure you are in Line Tool mode, the click on the line with the I key held down, and insert new points.
Now I set things up so SB knows that the Scenery Folder for the airport I am working on is my default BGL location. When you compile, a new BGL will be created with the prefix CVX. To compile, go to Select - All Lines, then click the green right arrow on the toolbar. It should have ticked Terrain Vectors. Select Copy BGL Files to BGL Folder and hit Compile. So long as you set up the BGL folder in the Project Setup all will be well. Now relaunch FSX and you should see traffic flowing along your roads. Traffic does tend to disappear and reappear, a quirk of FSX, and Semi's might drive through your airport.
Hope this is helpful