I suspect that JP's density is actually a bit higher than that today, given that it was 8500/sq mile based on 2010 population. Regardless, it's important to consider that JP is miles outside the city center. It isn't so much a model of super dense housing as it is a good way to up the density of neighborhoods that might otherwise only support 3500/sq mile. JP represents a good middle ground between the car-centric deep suburbs and the extremely dense city center.