It was with considerable interest that we read the contention in these pages on Sunday by two members of Boulder’s Transportation Advisory Board that concerns about a lack of data to support the reduction in auto lanes on Folsom Street are misplaced.

“There’s been much outcry about the supposed lack of data, but the assertion isn’t true,” wrote Bill Rigler and Andria Bilich, two members of the five-member panel that recommended the project. “Significant ‘before’ data exists . . . .”

Six days earlier, Daily Camera columnist and pro cyclist Mara Abbott revealed the results of her research into this question. She found that “before” data for the relevant portion of Folsom published on the city’s website consisted of a single data point — observation on one day — at each site. “As in 1/365 of a year,” she wrote. “Or 1/1,095 of three years.”

That observation was intended as a contrast with the recommendation from the Project for Public Spaces, an advocate of so-called “right-sizing” projects, that “statistics are ideally measured over a multi-year period. Periods of three years before and after right-sizing a street are standard.”

So when Rigler and Bilich claimed “the assertion isn’t true,” we went back to the city’s website to double-check Abbott’s research. Like her, we found single, random “before” data points for the sites on Folsom that were measured at all. For example, pedestrian crossing numbers at Folsom and Pearl were measured on April 28 of this year. At Folsom and Canyon, the count was taken Aug. 7 of last year.

Was pedestrian traffic on those dates typical? Who knows? You would have to increase the size of the data set dramatically to find out.

Bicyclist volume at Folsom and Valmont was measured on July 9, 2013. At the intersections of Folsom and Pearl and Folsom and Canyon, the city counted bikes the same day it counted pedestrians.

Auto traffic counts on Folsom appear to have been taken on a single day in either April or June of this year, although only the month is noted in the chart offered by the city. “Traffic neighborhood diversion” counts — a key metric in determining where traffic goes when important arteries shrink — were taken around Iris Avenue, another intended target of downsizing, but there is no similar chart offered for Folsom.

Various advocates of the project have suggested that more “before” data exists than has been published. If that is the case, we urge the city to release it. If not, we must conclude Abbott was right and the claim by Rigler and Bilich that “significant ‘before’ data exists” is either an extremely generous characterization of these isolated, random data points, or refers to the more extensive data surrounding Iris — which does not help in the current debate over the Folsom experiment.

There are two ways to pursue a project like this. One is to collect enough data to make it statistically valid, then select a street for shrinkage based on that data, choosing one with relatively low traffic volume and adequate nearby alternative routes, as the Project for Public Spaces recommends.

The other approach is to decide on the basis of political ideology that you like this idea, adopt an Orwellian title — “right-sizing” — that suggests you’re right before the debate even begins, then hustle out to collect a few random data points in an effort to support a decision you’ve already made.

The lack of “before” data on Folsom makes it easy for critics to conclude that cycling activists on the Transportation Advisory Board, in the city’s transportation department and on city council chose the latter course. For example, the Project for Public Spaces reports that “streets with more than 15,000 average daily vehicles often demand an operational analysis to closely look at impacts before implementing a four to three-lane conversion.”

The city’s website offers only two auto data points on Folsom — “average daily traffic” of 15,780 at Bluff Street on the day they counted in April, and 18,970 at Canyon Boulevard one day in June. Oddly, both of these counts are northbound traffic, according to the city’s chart. It offers no full-day “before” count for southbound auto traffic at any point on Folsom.

It does not take a Ph.D. in statistics to know that single, random data points do not lend statistical validity to assumptions about “average daily traffic.” The data published by the city do not reflect any attempt to gather information during different seasons of the year. There is no winter Folsom data. Any contrast offered now between “before” and “after” traffic counts is based either on single “before” data points that lack statistical validity or other “before” data the city has not published.

If the city has more robust “before” data for Folsom Street, we urge it to publish it. If it doesn’t, we urge the Transportation Advisory Board to stop claiming it is more robust than it is. Lacking sufficient “before” data on Folsom reflects on the city’s competence; not telling the truth about it reflects on its integrity.

—Dave Krieger, for the editorial board. Email: kriegerd@dailycamera.com. Twitter: @DaveKrieger