The one AOPA (AOPA's Real-Time Flight Planer power by Jeppesen) has does that, I
laned a trip from Oklahoma to California PWA - RIR via airways at a too low an
altitude (7500) and it did some weird stuff. When I set the altitude at 10500,
it did a good job.

But this one is a free down-load (as long as you are an AOPA member)
and does most of jobs OK.