Duniway Park

This park is a Portland icon. It has a big track open to the public. Chances are that if you reside in the area, you have seen it several times. The location near downtown is prime real estate.
It was great to visit. There are benches besides the tracks along with restrooms and a drinking fountain. The size of the track in conjunction with the location at the bottom of the hill make this all the more noticeable.
Also, at the top, there is a garden. Plenty of nice views can be seen of the city as I you walk from OHSU to PSU, two colleges, as I walked. This wonderfully represents the city.
Chances are that you will enjoy Dunsmuir Park.

One of my favorite places to go running. There is almost always people at the track and it is a wonderful place to be.

a very busy track used for a number of marathon training groups, kids track teams, and the gym that’s right next to the track.

I’ve been using this track to train for a 5K, and I’m a fan. It’s reasonably close to almost anywhere in town, there’s a decent amount of parking both on and off-​street, and it’s open all the time. (Although you’ll have better luck using it after 5:30PM on weekdays, once the high-​school kids are done using it.)
It’s made of rubber sneaker soles, so it’s nice and easy on the shins & joints, and it has an all-​weather clock in case you don’t have your own timer.

This is one of my favorite places to run. The track is a nice, all-​weather (which for Oregon is a handy thing) track with eight lanes, so people of all abilities/​speeds can work out in harmony. There’s also a nice big digital clock at the finish line so you can keep track of time, intervals, whatever. There are bathrooms that are… functional. They are not outhouses and they work, so that’s convenient. Not sure what the hours on those are.
The location of the track is beautiful and perfect for working out. If you choose to stay on the track, you can enjoy the variety of trees and shrubbery hugging Marquam hill. Many of the trees light up in oranges and yellows and reds in the fall, making the run especially nice then. A paved path up from the track leads up to a woodchip trail (perfect for recovery running, easy on the joints) and the Terwiliger running/​biking path up to OHSU. So if hills are your thing, you can take advantage of that from the track, too.