The simplest way (although not necessarily the safest way) to incorporate HIIT into your commute is to sprint for every light.

You could also do something like 30s on/off intervals. Those don't require power or cadence, just the timer function on your computer or watch. Again, very simple. 30 seconds on means full gas, as hard as you can go, for the full 30". Then recover for 30" by coasting or soft-pedaling. The problem with strict time intervals is that they often don't work well on commutes where you have lots of stop signs and stop lights.