To get rid of poison ivy, is there anything "better" than Round-Up?

By "better", I mean any of the following:

- less expensive (price per hundred square feet of weeds killed), or

- quicker (don't have to wait three weeks for weeds to die, or

- more effective (one spray does the trick; no need to re-apply)


Or is Round-Up the best available herbicide?

I am putting a half-mile-long trail in my woods, and I need to kill all
the undergrowth on and around the trail so people can walk comfortably.