Splitting "cardio" and the nonstop 1.5 mile up, I would say the cardio is the actual goal while the distance was more of an attempt to make the "Cardio" into a solid goal.
In that case, most of us here would recommend either metcons (use the search feature/Google, or see Crossfit for sample workouts) or HIIT (high intensity interval training), or both.
You can do intervals ("sprints" or max effort for certain distance) on a bike, swimming, running, even jump roping.
Do a Google search for "Tabata protocol" as well.
The 1.5 mi goal isn't necessarily "bad," but it doesn't directly translate to parkour. If you have another reason to run that distance, no worries.
If you only want to have the benefit for parkour, I'd suggest running 400m sprints two or three days a week. Go to your local high school/junior college and run a lap around the track: that's 400m (if it's a standard-size track, around the football field). Rest 5 minutes between sprints. Try 4-6 sprints, make sure you run as hard as you can for a pace that you can keep up for the whole lap.
It should be really hard and you should feel exhausted afterward. By the time you go to start your last sprint, you should feel like you want to jump into your computer, magically travel through the internet, find me and destroy me and my unborn children cell by cell for suggesting you do something sooooo f#cking exhausting. That's how you know you're doing it right.
