DUI Stops: Weaving

A traffic stop is how most driving under the influence investigations start. In order to pull somebody over, the Fourth Amendment requires that officer’s have reasonable and articulable suspicion that a driver has broken the law - a moving violation is usually all it takes. Examples of a moving violations include speeding (Vehicle Code section 22350) and running a stop sign (Vehicle Code section 22450). But what about weaving? How does the Vehicle Code define weaving? What kind of weaving would give an officer reasonable suspicion to pull someone over? Weaving seems like a vague term likely to lead to arbitrary traffic enforcement stops, right? I’ve represented hundreds of clients over the years who were arrested and charged with driving under the influence after getting pulled over for weaving. Let’s talk about it. But first! Legal opinions and statutory interpretations are subject to change due to the dynamic nature of case law and judicial rulings. As legal precedents continuously evolve and metastasize, future decisions may alter or refine the interpretation of a statute. Or a statute may be amended or repealed altogether. Therefore, opinions expressed below should not be construed as definitive or exhaustive. They should also not be relied upon when making decisions about your own case (or anyone else’s case if you happen to be a lawyer reading this.)

With that out of the way…

Weaving isn’t a term defined in the Vehicle Code. Rather, a person is being pulled over for a violation of Vehicle Code section 21658, failing to maintain a lane. But courts use the word “weaving” and so I’ll use it too. Here’s the rule: Weaving may only form the basis for reasonable suspicion if the weaving is “pronounced” and is observed for a “substantial” or “considerable” distance. (People v. Perez (1985) 175 Cal.App.3d Supp.8, 10; People v. Bracken (2000) 83 Cal.App.4th Supp.1, 4.)

A number of California and Federal cases have addressed what it means to weave in the context of traffic enforcement stops. The Tenth Circuit explained it best: “[…]if failure to follow a perfect vector down the highway or keeping one's eyes on the road were sufficient reasons to suspect a person of driving while impaired, a substantial portion of the public would be subject each day to an invasion of their privacy.” (U.S. v. Lyons (10th Cir. 1993) 7 F.3d 973, 976.)

Motions to suppress on these grounds are tough to win but I’ve seen it happen. Probably done it a time or two in the past. If you’ve been arrested or charged with driving under the influence and have questions about your case, give me a call for a free 30-minute in person consultation at my office in Chico.