By W. Clay Abbott
TDCAA DWI Resource Prosecutor in Austin
The saga continues as the most helpful traffic offense in driving while intoxicated (DWI) enforcement continues to be housed in the most difficult statute to interpret. Yes, it is time to talk about Failure to Maintain a Single Lane (FTMSL)[1] again.
The Court of Criminal Appeals, in its recent Daniel v. State[2] decision, gave a bit of a reprieve to the suppression slaughter in DWI cases caused by Hardin v State[3]. In Hardin, the CCA reversed the plurality opinion in Leming v. State,[4] which found the offense of Failure to Maintain a Single Lane had only one element: failure to drive within a single lane. Hardin concluded that the offense has two elements: failure to maintain a single lane and doing so when it was unsafe.
In Daniel, the CCA helpfully laid out how the various intermediate courts decided the issue before Hardin: The First, Second, Third, Fourth, Sixth, Ninth, Thirteenth and Fourteenth Courts of Appeals all said the offense had two elements, while the Seventh, Eighth, Tenth, Eleventh, and Twelfth held there is just one. Daniel concluded that the state of the FTMSL law was so uncertain before Hardin, suppression of the evidence was not required if an officer relied on the law in his appellate jurisdiction.
Specifically, the Court of Criminal Appeals addressed whether the State could claim the “mistake of law” doctrine in arguing a traffic stop was reasonable—despite the officer failing to correctly predict whether the Court would dodge right or left in 2022 and exactly what the law was at the time he made the stop. If 12 appellate courts and nine CCA judges could not agree on an answer, the officer made a justifiable mistake of law. That being the case, the stop in Daniel was reasonable and did not require suppression because it occurred before the November 2, 2022, opinion in Hardin.
If you are prosecuting an intoxication case where the stop was based on FTMSL and the offense date was before November 2, 2022, please use the very helpful Daniel decision to avoid suppression. If the offense date is later than that, there are still two possible ways to combat a motion to suppress, and in DWI cases, you should always be making a record for and arguing both.
Two good arguments
1. FTMSL as reasonable suspicion for DWI. In Hardin, the traffic stop was not for DWI. A Corpus Christi police officer followed Sheila Jo Hardin, who was driving a U-Haul truck, because he had received a BOLO (“be on the lookout”) bulletin earlier regarding a U-Haul suspected of involvement in multiple burglaries.
That aside, there are numerous mentions in the many opinions in Hardin that the traffic behavior described as Failure to Maintain a Single Lane could be part of reasonable suspicion of DWI, which makes great sense.
Inability to keep a vehicle in a road’s marked lanes is directly connected to the visual impairment detected in horizontal gaze nystagmus (HGN). When nystagmus has an onset before 45 degrees (the second HGN clue), it means the eyes no longer have as wide an active field of vision. While an unimpaired driver can look straight ahead and see lane markers at 45 degrees in each direction without moving his eyes, an impaired driver with HGN cannot. An impaired driver must move his eyes to clearly see the lane lines. When a driver moves his eyes, he tends to turn his head and then the steering wheel too. (Read the published study in this endnote for a much deeper analysis of the science.[5]) Experienced officers, or perhaps a drug recognition expert (DRE) or standardized field sobriety test (SFST) instructor, can explain this completely expected result of HGN to the court and, just as importantly, get the explanation into the appellate record.
In addition to causing HGN, alcohol and every category of drug covered by DREs and toxicology labs also impair executive function. Executive function is the ability of the frontal lobe of the brain to focus, make effort, execute complex motor controls, and complete the surprisingly difficult physical and mental task of keeping a speeding vehicle in a fairly narrow lane while continuing to perform all of the other driving and non-driving tasks a driver must do. Quite simply put, the failure to keep a car in a lane is a very good “vehicle in motion” clue of impairment. In fact, experienced officers relate that it is the most common and dependable clue of impairment. This information also needs to go in the record.
2. Prove both elements. While prosecutors should argue reasonable suspicion of DWI, don’t give up on proving both elements of this traffic violation. Gather information to prove the lane violation(s) occurred and that they were unsafe, and prepare the officer and the facts of the case to do just that. First, have the officer describe the extent and frequency of the lane violations. Get solid detail here. In Hardin, “tires touching the line once for a second on a curve” were hardly the facts we usually see in a DWI case. Have the officer discuss how often he sees lane violations as opposed to what makes him conduct a stop for Failure to Maintain a Single Lane.
To prove the lane violations were unsafe, use the in-car video to establish other traffic on the road at the time the suspect was driving, if not at the exact moment of the stop. Ask the officer to explain the need to react to a violation before it causes a crash instead of after a collision has already happened. (I know this seems a little obvious, but after I read the opinion in Hardin, it must not be.) Ask the officer to describe the road and traffic patterns. High-speed-limit roadways pose a danger because greater speeds give drivers less time to react, and crashes are particularly violent at faster speed. City streets, while slower, have their own difficulties, such as crossing and merging traffic, often with little warning. Does a late night or busy traffic time make the violation more dangerous? Make sure that every other observation, as well as time of day and location and weather conditions, also make it into the record—the ruling on the stop should be based on the totality of the circumstances.
If you don’t have the officer walk through all his observations and put it all on the record, the eventual appellate opinion in your case may be the next one I have to rant about.
Conclusion
Failure to Maintain a Single Lane is a great clue in impaired driving cases that unfortunately carries its own appellate burden. While recent cases have certainly made things harder for prosecutors, we have two silver linings. First, the confusion concerning how many elements are in the offense is over: There are two elements for failing to maintain a single lane. The second silver lining is that there are ways to save these cases—it just takes some preparation and a better record than we have been making.
Endnotes
[1] Tex. Trans. Code §545.060.
[2] 683 S.W.3d 777 (Tex. Crim. App. 2024).
[3] 664 S.W.3d 867 (Tex. Crim. App. 2022).
[4] 493 S.W.3d 532 (Tex. Crim. App. 2016).
[5] Burns, Marcelline; Southern California Research Institute and the National Highway Traffic Safety Administration. “The Robustness of the Horizontal Gaze Nystagmus Test,” 2007. Available at https://rosap.ntl.bts.gov/view/dot/1821.