Portland's been one of the nation's prime growth markets since even before the recession, but now it's facing some of the challenges of success, including a housing squeeze and traffic congestion. Portland still has strong growth prospects, according to the speakers at our Portland State of the Market event, but public and private interests have to be careful—and thoughtful—in the years ahead.

In the hotel sector, Portland has seen double-digit RevPAR growth each year over the last six years, a dynamic that hasn't ever happened before, according to Provenance Hotels president Bashar Wali, whose company owns and operates largely boutique hotels in Portland and Seattle, but now also in New Orleans and Nashville. He kicked off the event with an interview by Julie Gibson, executive director of the Portland State University Center for Real Estate.

Driving the growth: a lack of new supply since the recession, and sophisticated travelers (and sophisticated investors) turning their attention to Portland. Portland has high barriers to entry, including high construction costs and a lack of land. Even so, much more hotel supply is beginning to come online: 2,100 rooms in the next two to three years, which will impact Portland's 90% or so occupancy.

What has made Portland so successful at attracting people (especially Millennials) and businesses in recent years, and can it continue? Our speakers stressed authenticity as one of the main ingredients of success. That goes down to the granular level in making a neighborhood a neighborhood, starting with the retail mix at the street level, as well as the right kinds of residential and office space.

Creating authenticity in new buildings is a challenge, but it's possible if they have personality and are human-scaled. Millennials, particularly those of the creative class, are looking for experiences outside their dwelling space. Mixed-use development helps make that happen better than any other kind of development.

Snapped: TMT Development CEO Vanessa Sturgeon and ZGF Architecture managing partner Jan Willemse.

Portland's housing market has had a good run, but now there's growing risk in the market, our speakers said. It isn't any one factor, but many things put together, especially recent changes—or potential changes—in public policy. There will be a surge of projects over the next few months to get in under the old rules, but after that the outlook is less certain.

Portland recently completed an update of its comprehensive plan, adding inclusionary zoning, which might constrain housing supply and push rents up even further, the complete opposite of its intention. The motives of the policy might be sound, but our speakers characterized the new rules as too much stick and not enough carrot. It's a major uncertainty for the housing market.

Shown: Interior Office Solutions director Melody Bridges, who moderated, and Cairn Pacific principal Thomas DiChiara.

Affordable housing, and homelessness for that matter, isn't something that will be solved either by public initiative or private activity, but a concerted combination of initiatives. There are probably a half dozen things that need to be done, all at the same time. The city needs the kind of decisive public/private leadership that it used to have, the speakers said, such as when the Pearl District was redeveloped.

Traffic and other infrastructure issues are likewise serious challenges for Portland, and traffic's going to get worse before it gets better, especially as people move to town and bring their cars, which will compete with space for other modes of transit. There's been no investment in roads recently, and none planned—which might help drive Millennials to Downtown, but will also make traffic worse. If Portland reaches a choking point for access, that will affect livability in the urban core, and no amount of authenticity will overcome that.