With traffic congestion and skyrocketing housing prices high on people's minds, the percentage of Palo Alto residents rating their city a great place to retire has reached a new low, according to an annual survey commissioned by the City Auditor's office.

The National Citizen Survey, a statistically valid study conducted by the National Research Center, found that Palo Altans by and large like living in their home town, with 88 percent ranking the overall quality of life as good or excellent. This good news, however, comes with a buzzkill caveat: 2015 marked the first time in the survey's 13-year history that the number has dipped under 90 percent (it was 94 percent in 2012 and 91 percent in both 2013 and 2014).

The percentage of people rating Palo Alto as a "good" or "excellent" place to retire has slipped markedly, going from 68 percent in 2006 to just 60 percent in 2014 and 52 percent in 2015. Meanwhile, the percentage that gave the city good grades for "variety of housing options" went down from 27 percent in 2014 to 20 percent in 2015.

The outlook looks bleakest to residents in the south Palo Alto neighborhoods of Barron Park, Charleston Meadows, Esther Clark Park, Greater Miranda, Green Acres, Monroe Park, Palo Alto Orchards and Ventura, which are grouped together as Area 4. Only 45 percent of the surveyed residents in this area gave the city the top two ratings as a place to retire.

Things didn't look much better from the perspective of Area 5, which is also in the south and includes Adobe Meadow, Fairmeadow, Greenmeadow, Palo Verde and Walnut Grove. Only 46 percent of the respondents in these neighborhoods gave Palo Alto the top two ratings as a place to retire. By contrast, about 60 percent of the residents in the downtown neighborhoods north of Embarcadero gave the city a "good" or "excellent" rating when asked about retirement. Overall, while 59 percent of north Palo Alto (generally, north of Oregon Expressway) gave the city the top two grades in this category, only 47 percent of south Palo Altans did the same.

To be sure, the survey findings weren't all bleak. The vast majority of the respondents in the 2015 survey continued to give Palo Alto the top two grades as a place to raise children (87 percent, down from 93 percent in 2014), and 90 percent ranked their neighborhood as a good or excellent place to live (down from 2014's level of 92 percent).

And when it comes to the library system, Palo Altans can hardly be happier. Last year, 91 percent of the respondents gave the "good" or "excellent" rating to local library services, a happy jump from the 81 percent who did so in 2014.

But when it comes to traffic, housing and development in general, frustrations continue to grow. Only 49 percent of the respondents citywide (and only 44 percent in the southern half) gave the city high ratings when asked about "overall quality of new development" -- a 13 percent decline from the 2006 level. And when asked about traffic flow on major streets, only 31 percent gave Palo Alto a positive grade (this is down from the 2006 level of 39 percent).

Other questions relating to mobility proved to be equally sobering. Only 36 percent of the respondents gave the city top grades in "ease of parking" and only 26 percent said "excellent" or "good" when asked about ease of travel by public transportation, down from 36 percent in 2014.

But it was Palo Alto's housing supply, rather than transportation system, that once again emerged as the city's most glaring weakness. The percentage of people giving the city good grades for "variety of housing options" dropped from 27 percent in 2014 to 20 percent last year. And when asked about availability of affordable housing, only 5 percent of the respondents from the northern half of the city, and 10 percent from the southern, gave Palo Alto top grades (overall, 8 percent of the respondents gave Palo Alto good grades on affordable housing, down from 11 percent in 2014). And when asked about the cost of living in Palo Alto, 8 percent gave the city the top two grades while 64 percent rated it as "poor."

The problem of insufficient affordable housing is far from new in Palo Alto, though the survey suggests that it is now becoming an increasingly pressing priority for local residents. Last October, in a discussion about the city's Comprehensive Plan, dozens of residents attended a council meeting to lobby for more housing options. They included recent college graduates who grew up in Palo Alto and can no longer stay here; senior "empty nesters" who don't have the options of downsizing to smaller units; and even local attorneys and tech workers.

The topic also loomed over this week's discussion of the Comprehensive Plan between the council and the Citizen Advisory Group that is helping the council update the broad vision document. Again, many members of the citizens group called for the council to consider policies that would promote more housing options and enable a greater diversity among the local population.

Elaine Uang, a downtown resident who serves on the citizens panel, cited the lack of diversity in her comments to the council. There are seniors, she said, who are being "ushered out of the community even though they lived here for a long time because they can't afford it and they don't have options."

Uang said that other members of the group referred to instances in the past when they'd walk down the street and see their kindergarten teachers. With current housing costs, such a scenario is all but impossible today, she said.

Lisa Peschke-Koedt, who also serves on the panel and who works at Cisco, said Palo Alto was much more diverse when she was growing up. Her parents, she said, were "lower middle class" and didn't have much money.

"I miss some of that and I don't want to lose that -- the idea of having seniors, kids and people with less money, and housing for teachers and police," Peschke-Koedt said. "I think that's a good objective to have."

The council largely agreed Tuesday that the updated Comprehensive Plan should include policies for encouraging more housing, though what exactly those policies will look like remains to be seen. In recent months, council members have talked about encouraging more accessory-dwelling units (also known as "granny" or "in-law" units) and creating incentives for the creation of small apartments in transit-rich sections of the city.

Next month, the city will release the draft Environmental Impact Report for the updated Comprehensive Plan, which is expected to evaluate at least two different scenarios that include more housing. One, known as "Housing Reconsidered," would increase housing densities in downtown, near California Avenue and in other areas close to transit and services. Another scenario, proposed Tuesday by Councilman Tom DuBois, would focus on reducing the city's gaping jobs-housing imbalance by promoting more housing and slowing down job growth.

Housing, traffic and the burdensome cost of living aren't the only areas in which Palo Alto scored lower on the National Citizen Survey than most other surveyed jurisdictions. Local residents were also less likely than their counterparts elsewhere to watch a local public meeting or participate in religious activities.

The city scored far higher than most jurisdictions in a host of categories, including education opportunities, employment opportunities, ease of walking and biking, shopping opportunities, K-12 education, economic development, city parks and the city's overall appearance. When asked about Palo Alto as a place to work, 87 percent ranked the city as "excellent" or "good."