As a criminal defense lawyer I love the cases that discuss how cars on not trains on rails. Therefore, some level of weaving is perfectly acceptable. As a DUI defense attorney, I cannot tell you how many times my clients were pulled over because the police officer observed my client weaving. Much Kansas case law is in on the side of the defense regarding this issue. Unfortunately, in 2009, the Kansas Court of appeals made a decision, which convoluted this area of the law. State v. Chavez-Zbarra, the Court decided that failing to comply with K.S.A. 8-1514 is an absolute liability offense. In other words, they seem to believe in zero tolerance for driving into the other lane. The other cases rather appear to analyze the specific situation, such as driving conditions, other traffic, and etc. That seems to make more sense, considering how 8-1514 actually writes in exception even.
In State v. Chavez-Zbarra, the district court actually suppressed the evidence. However, the appellate court reversed and remanded, noting that there is a difference between K.S.A. 8-1514, left of center and K.S.A. 8-1522. The judges said that K.S.A. 8-1522 had no application in this particular case. Kansas Statute 8-1522 deals with staying within a driver's lane. Kansas Statute 8-1514 deals with not driving into the lane of oncoming traffic.