Munhall is safe but it borders Homestead which is not. There are regularly shooting there in the early AM hours that are reputedly gang related. That being said, Homestead is pretty much a bigger draw with regards to dining and nightlife than West Mifflin which borders it to the south. You just have to be mindful of crossing the train tracks because some pretty long ones roll through Homestead during all hours of the day and there's no going around the crossings. The nearest access to the Parkway is to go across either the Homestead High Level or Glenwood bridge but the on ramp is in Squirrel Hill and it can be a nightmare during rush hour.