Baird's on B in Lake Oswego could be a good choice. It's a decent size place with a few large tables, my wife meets there with her friends quite often. Food is great and they have a decent happy hour. Parking and safety are certainly not an issue.
http://www.bairdsonb.com/

And I understand Pietro's has made a bit of a comeback with new ownership, I haven't been there in years but the Milwaukie location would be convenient for most, big parking lot, big restaurant.