¶28 As in Waldner, the police officer in the present case did not observe any actions that constituted traffic violations or which, considered in isolation, provided reasonable suspicion that criminal activity was afoot. However, when considered in conjunction with all of the facts and circumstances of the case, Post’s driving provided Sherman with reasonable suspicion to believe that Post was driving while intoxicated.
¶35 …. Sherman’s testimony indicates that Post’s weave was between five feet and nine feet, based on his individual estimates of distances. Sherman further testified that Post’s vehicle moved laterally ten feet.
¶36 However, the width of Post’s weaving is not the only specific, articulable fact in the case. It is noteworthy that the single lane here, described as between 22 and 24 feet, is approximately twice as wide as the standard single lane.  Post’s vehicle moved in a discernible S-type pattern within that single lane, and it repeated that S-type pattern several (or “a few”) times for two blocks. When Sherman first observed Post’s vehicle, it was “canted into the parking lane” and “wasn’t in the designated traffic lane.” Finally, we note that the incident took place at 9:30 at night. While this is not as significant as when poor driving takes place at or around “bar time,” it does lend some further credence to Sherman’s suspicion that Post was driving while intoxicated. 
¶37 When viewed in isolation, the individual facts that Post was weaving across the travel and parking lanes, that the weaving created a discernible S-type pattern, that Post’s vehicle was canted into the parking lane, and that the incident took place at night may not be sufficient to warrant a reasonable officer to suspect that Post was driving while intoxicated. As this court stated in Waldner, “[a]ny one of these facts, standing alone, might well be insufficient.” 206 Wis. 2d at 58. However, such facts accumulate, and “as they accumulate, reasonable inferences about the cumulative effect can be drawn.” Id. We determine, under the totality of the circumstances, that Sherman presented specific and articulable facts, which taken together with rational inferences from those facts, give rise to the reasonable suspicion necessary for an investigative stop. Accordingly, the stop did not violate Post’s constitutional right to be free from unreasonable searches and seizures.
No bright-line rule; deviation within a lane alone does not either allow or inhibit an investigatory stop: fair enough, but what more was there on these facts? Do the sparse additional facts really add any heft to reasonable suspicion? When you get right down to it, about all they had was weaving within the lane plus the time of day was 9:30 p.m. The court concedes that the time isn’t really significant, so it seems to boil down to weaving within-lane after all, even if the court doesn’t want to say so. What the court does say is “that this case presents a close call,” ¶27, creating a fair assumption that these facts present the outer limit of what the court will permit. Similar driving in the afternoon might well not support a stop. You’d be hard pressed to say exactly why time of day matters so much, but the court has itself established the ground-rules and they include the idea, defensible or not, that late-evening driving weighs in favor of suspicion; an earlier time must necessarily weigh less if not against. But preoccupation with time of day shouldn’t obscure the extent of “weaving”: it went on in a “pattern” for two blocks in a lane twice the width of a “standard” lane, which means that the “deviating” was pretty aggravated. Hard to escape the idea that the court figured Post was simply fortunate to be in a very wide lane and would’ve gone well over the center line of a normal roadway. To be sure, that’s not explicitly what the court said, but its stress on the absence of any bright-line rule and its failure to come up with anything else doesn’t leave much by way of alternative.
The Chief Justice in (partial) dissent identifies the problem as an absence of relevant fact-finding. (“The circuit court made no findings of fact,” ¶47.) The majority, the dissent indicates, goes awry in filling this vacuum with its own fact-finding, ¶¶49-53; the case should be remanded so a proper record can be made, ¶59. Well, this case is done and it won’t be remanded—what’s the lesson for the practitioner? In architecture, form follows function, but a similar dynamic in law would be result-oriented; hence the obsession with process, more or less inverting this principle so that it is restated as, substance follows procedure. Which is just a fancy way of saying, in the right case and under the right circumstances you might have to press the trial court to make findings of fact. Might be a lesson, too, for appellate practitioners. You already know how useful demonstrative aids are for jurors, but keep in mind that appellate judges aren’t any different (well, not in this way at least). Trust the Chief Justice to remind us, ¶58, citing Coffey v. N.E. Ill. Reg’l Commuter R.R. Corp., 479 F.3d 472, 478 (7th Cir. 2007), of:
… Judge Richard Posner’s comment in a recent case …: “This case illustrates the curious and deplorable aversion of many lawyers to visual evidence and exact measurements (feet, inches, pounds, etc.) even when vastly more informative than a verbal description.”
You can’t go wrong when you quote Judge Posner, so here’s another, from U.S. v. Boyd, 475 F.3d 875 (7th Cir 2007) (appending downloaded Google satellite photo of scene of crime so everyone, appellate court included, could have a good visual inspection of the scene):
… The judge made no finding concerning the number of persons on the streets near the shooting (another conflict in the evidence that she did not try to resolve) or whether any persons were in the alley when and where the shooting took place. There was also no evidence on whether there are apartment buildings as well as office buildings in the vicinity of the shooting.
Despite these gaps, we are reasonably confident that the Indiana courts would hold that firing multiple shots from a high-powered gun in downtown Indianapolis for no better reason than an excess of animal spirits creates a substantial risk of bodily injury within the meaning of the Indiana statute.
To avoid the wrong impression: no one’s saying Post’s counsel could let alone should have done more. It’s just that even well-litigated cases allow a certain amount of extrapolation, which in this instance would be: it’s wise to keep in mind for any given case that there’s an increasing amount of publicly accessible information that the court is increasingly interested in.