Originally Posted by
reedreeder
length is the most important part. most track cranks are 165mm, which gives better ground clearance.
While length is important, most road and track cranks are available in a variety of lengths, usually in 2.5 or 5 mm increments, from 165mm to 175mm. So in that regard track and road cranks are not different.
For all practical purposes, you will notice little difference between track and road cranks. If you use a track hub and track crank, paired with the correct BB you'll have an easier time achieving a straight chainline. Thats about the only benefit of track cranks used on the road.