Generally, weaving within one’s own lane of travel is not unlawful and without more does not establish lawful justification for a police office to pull you over.
Under some circumstances, this wholly lawful behavior can provide sufficient cause to justify a detention for a suspected violation of Vehicle Code section 23152. The California courts first addressed the issue of “weaving within a lane” in
People v. Perez (1985) 175 Cal.App.3d Supp. 8. Today, the standard annunciated in
Perez remains the benchmark by which these types of cases are measured.
In Perez, the officers followed the defendant for three quarters of a mile as he weaved within his lane two feet in either direction for the entire distance. (Id. at 9.) In finding reasonable suspicion to stop Mr. Perez, the court held that “pronounced weaving within a lane provides an officer with reasonable cause to stop a vehicle on suspicion of driving under the influence where such weaving continues for a substantial distance.” (Perez, supra 175 Cal.App.3d Supp. at 11-12., emphasis supplied.) The court intended it’s holding to be read narrowly given its choice of adjectives and the corresponding facts of that case. Likewise, in
People v. Bracken (2000) 83 Cal.App.4th Supp. 1, the defendant was stopped because an experienced officer observed extremely pronounced weaving within the lane for approximately one-half mile. In both
Bracken, the defendants were weaving within their lanes, but had done so for a considerable distance. Further, the weaving was severe and pronounced.
The weaving within your lane issue was also addressed by the Ninth Circuit Court of Appeal. In United States v. Colin, 314 F.3d 439 (9th Cir. 2002), the Ninth Circuit held that only in cases where the weaving was pronounced and where the distance traveled was substantial did the
Perez holding have valid application.
In Colin, the police observed the defendant for 35-40 seconds, during which time he drifted to the far side of the lane he was in for approximately 10 seconds, before drifting back toward the other side. Colin then made a legal lane change, and proceeded to repeat the drifting conduct. The Court held that these circumstances did not warrant application of
Perez. The Court explained that “if failure to follow a perfect vector down the highway...[was] sufficient [reason] to suspect a person of driving while impaired, a substantial portion of the public would be subject every day to an invasion of their privacy.” (Colin, supra at 446.)
Courts have limited their decisions in the weaving, drifting and straddling cases to permit a stop only in those cases where the movements are pronounced, recur over a substantial distance and specifically affect other traffic or while speeding.