How can I apply tire track imprints on a terrain?


I want to achieve the effect of tire tracks on a terrain like the one pictured below (Image 1).

Ive tried about 4 different methods so far and none have worked out:

IDEA 1: (See Images 2&3)
I tried creating a spline mesh using a road section and edited the material so that it had transparent elements to try and blend it with the terrain below.
This is all well and good but the problems I face using this method are that if I have collision ON and you come off the track and then you try to rejoin it, the vehicle can often get snagged on the mesh edging. If collision is OFF, because the terrain doesnt conform 100% to the spline mesh you end up sinking through the floor at times. Additionally there is a horrible effect when you drive uphill where you can see under the road. (It was difficult to show in a screenshot, but you might get an idea if you look at my 3rd image).
I then tried to use the LayerName tool on the spline to blend a texture onto the landscape, but as it only sets one single texture in one direction I can’t really do much with it.
My next idea was to create a black and white brush and manually stamp out the normal pattern of the tracks along the terrain. This was also a disaster idea.
Finally I thought of creating a series of tire track decals and placing them alon the full length of the track but I’m told this can be extremely heavy on performance and wouldnt give the desired effect…

So I return to the UE4 Forum and hope someone can help me out.
Ideally a video tutorial showing how to get this effect would be fantatic and also if there is a way to get this effect without using spline meshes, I would definitley favour that idea!

Patiently waiting…

Many Thanks