I play at a private club, believe me we have issues with slo-play, but it is much better than slo-play at public places, 5 hours no way! Our norm is 4-415 for foursomes and 345 for 3somes, we always use carts virtually no one walks, 10 min intervals.
Club ownership is committed to fast play to the point that design has been changed, removal of trees, reducing rough areas and height, cleaning wooded areas and adding RPAs where none existed previously. Of course some of those things have cost money but over time are improving everyone's golfing experience.
One other comment, I play with a group that travels both in and out of state and get to see a lot of courses, why are GC architects so bent on creating courses that are so hard that the general golfing public can't play them. Forced carries, tight fairways, lurking wooded areas, bunkers galore?? If you have ever played an older course designed back in the day and it has been restored or kept to their original designs, I think you will see a significant difference with modern tracks. They tend to be much more subtle, fairways more generous, rough cut so you can find balls, but still challenging.