But the 4 lane highway would be prone to traffic jams whereas the 8 lane
with the same amount of cars would be freeflowing....so the 4 lane would be
bottlenecked

No that's why I said a "single car". The car is the data and having a 4 lane
lane highway is plenty for that car to get from point A to point B. If there
were over 4 cars then the 8 lane highway would make a difference.