z-fighting on some transition pieces

[DaEgi01]

hey, I found some z-fighting issues on some transition pieces.
does not happen on all though.
my graphic card is a geforce gfx 1070.
I play in dx11 mode.
sun position is orthogonal to the roads. (sun) |||| <- roads
flickering can be spotted best at twilight (around ~6:00pm)
since it happens only on certain pieces, I think it is not the "normal rooftop flickering" that some ppl get, but actually something one could fix.

affected are the elevated to tunnel transitions of:
6 lane asym road 2+4 - texture looks out of place here
3 lane asym highway 1+2 - very strong flickering
two-lane highway - strong flickering on one side
national road
four-lane national highway - only very minor
four lane highway

ground to elevated transition:
four-lane national highway
four-lane highway
3 lane asym highway 1+2 - very strong flickering
two-lane highway
national highway

ground pieces:
3 lane asym highway 1+2 - very strong flickering at the borders