I made one for my commute.
[IMG]ecomodder.com/forum/emgarage-pic-popup.php?img=74ffad37b204194f2dd6f95ab5d4d41d.jpg[/IMG]
My commute is pretty uneven as well, about 4.3 l/100km to work and around 6.4 l/100km return (as reported by the over enthusiastic dash computer).
You need to be aware that this profile is based on ground level, not road level.
It ignores all the cuttings and bridges that the Highway uses.
Still interesting as a rough approximation though.