Friday, September 28, 2018

Public Transit and Third Bridge Equally Popular; Biking Satisfation Suspect in City Survey

The City published results from an annual survey this week, and the readings of it seem a little odd, misunderstanding greater precision than the survey actually offered.

In the report the City published, the survey consultant writes
Taken together, 18% are concerned with transportation issues such as roads, potholes, infrastructure, an additional bridge, public transportation, and traffic.
The framing on transportation may serve advertisers most
The paper echoed this:
The survey found residents consider homelessness and poverty to be the top issues they think Salem's elected officials should address (33 percent), followed by transportation issues such as roads, infrastructure, potholes and adding an additional bridge across the Willamette River (18 percent).
Both formulas are misleading, and the SJ's especially so.

The additional bridge share is 4% as "most important," not 18%. The figure of 18% came from 7% + 4% + 4% + 3%, the sum of:
  • Roads, potholes, infrastructure
  • Additional bridge
  • Public Transportation
  • Traffic Congestion
It is more illuminating to say that Public Transit and an Additional Bridge poll equally urgently. Moreover, if the margin of error is nearly 5% that's a total error bar of 10% on either side of the reported value.

And "fix it first" is a value meaningfully different from "solve traffic congestion." To conflate them and add them together conceals more than it reveals. Sure, both involve "transportation issues," but they have different valences.

It is also interesting to compare results to previous years:

"Most Important" in 2017

"Most Important" in 2016
In 2016 transit and the bridge were also equal. (See notes on 2016 and on 2017 surveys, also.)

Truly, it's not this easy to walk and bike in Salem in 2018
Some of the other data is suspect.

83% of people say it's easy to walk and bike in Salem?

Maybe walking, but not biking.

More specifically, the "very easy" response was 40% in 2016, 34% in 2017, and 54% in 2018. Really? What in Salem has changed an accounted for a 20% positive swing from 2017 to 2018? That's got to be noise.

Census data on commute to work, 2017
In any case, if it were so easy, why don't more people do it? In 2017 only 0.7% bike to work, and only 3% walk to work.

Those numbers are difficult to square with an 83% satisfaction rating.

Either the 83% figure is wrong, or the question is so vague and anodyne that it isn't getting a useful response. At a minimum it should be split into parts: When did you last walk, when did you last bike, how easy was it to walk, how easy was it to bike?

Survey writers could probably zero in on more specific critique. Overall it does not seem specific and rigorous enough to discern real problems, real successes, and real values and priorities. It is too superficial and prone to back-patting or complaint.


Anonymous said...

"What in Salem has changed an accounted for a 20% positive swing from 2017 to 2018? That's got to be noise."

Yes, there's a lot of noise in a small survey sample. Let's all concede on that.

But maybe (just maybe) people are noticing that there are more opportunities for both recreational and non-recreational biking when they see projects like the Minto-Island bike/ped bridge, the crossing treatment for bikes at Commercial Street and Union, bike lanes downtown on High and Church, etc. And maybe they are answering that there are more opportunities for easy biking for others, if not necessarily themselves. (I would answer that more playgrounds equate for a higher quality of life for the community, even though I don't use the swings and slides myself.)

Salem Breakfast on Bikes said...

What you are saying could be true in a way, but what it amounts to is an argument about symbolism: By planting these flags - Minto Bridge, High/Church bike lanes, Union St crossing, and the Geer Park facility you don't mention - Salem is doing a better job of signalling it looks like a place that should be good for biking.

And if biking in Riverfront, Minto, and Geer Parks is increasing, which is possible, because those facilities are real and useful, the survey is insufficiently granular in distinguishing between on-street and off-street biking.

But wouldn't it be more helpful to know - these are made-up numbers for the moment - that 60% of Salemites think it's easy to bike in our parks, but only 10% to run errands or go to work?

This is the more important takeaway, that the survey doesn't tell us anything meaningfully specific, and will be used to spin overbroad conclusions.

Especially because Salem has historically tried to displace biking from the street to parks, if the "approval rating" is really about parks facilities, it should be identified as such and not passed off as some general approval about bicycling.

Susann Kaltwasser said...

I was one of the people who got to answer this survey.

A few observations might help with some of your questions about validity.

First, the questions were such that you had to pick for a long list, but could only name one or three in some questions. If you were being asked a long list of what you think is most urgent, I can see homelessness getting more responses than potholes.

Second, they never asked to explain our answers or suggest items.

Third, it seemed like some of the questions were geared more to what would you be willing to pay for, rather than what do you want most.

Finally, the person that did my survey was not English speaking so it was hard to understand some of what they were asking.

On another topic, I heard a very interesting presentation by Public Works staff about sidewalks and why it is taking so long to get repairs and improvements. Might be a topic for some research and a blog.

Anonymous said...

Susan - I'd be interested in seeing or reading the presentation you mention. If possible, could you ask Public Works to post it on the city's website and then mention it here (or let the B.O.B know about it to create a new post). Thanks.