March 6, 2024 – Consider the following scenarios. First, you are driving in an unfamiliar area, out of your comfort zone. GPS barks that this is your exit now, so you have to make a sudden lane change in heavy traffic to get off the interstate. Second, riding your bike, when you are either approaching or actually at a stoplight/stop sign at an intersection, you suddenly realize that you need to turn right, not go straight. Third, on a road trip late at night, you are cruising on the highway, not another soul in sight; you are getting tired and need to pull to the side of the road for a break. What are the applicable rules of the road, specifically regarding use of turn signals (lamp and arm/hand)?
To help everyone on the road avoid potential civil and even criminal liability, this article examines the applicable state statutes, case law, and pattern jury instructions. In short, for your own and everyone else’s safety, it is best always to use turn signals. Wisconsin law distinguishes between lane changes, called “deviations from traffic lanes,” and turns.1
Deviations/Lane Changes
If a person wishes to deviate (change lanes) on a road that has been divided into two or more “clearly indicated lanes,”2 the driver “shall not deviate from the traffic lane in which the operator is driving without first ascertaining that such movement can be made with safety to other vehicles approaching from the rear.”3
Peter R. Heyne, Marquette 2010, has been an assistant state public defender (SPD) in the Trial Division, Green Bay office since 2015.
If there are not clearly indicated lanes, then the driver should not “move right or left upon the roadway unless and until the movement can be made with reasonable safety.”4
Unlike with turning/stopping (discussed in the next section), when deviating there is no specific signal requirement, but a rule of reason depending on the circumstances such as road conditions.5
The penalty for an unsafe lane deviation is a forfeiture of not less than $20 nor more than $40 for the first offense and not less than $50 nor more than $100 for the 2nd or subsequent conviction within a year.6
As the plain text states, there is no official requirement – not in the statute, case law, or pattern jury instruction – that a driver must first use a turn signal before deviating/changing lanes. However, even if not mandated, common sense suggests that the failure to use a turn signal could be a factor in the totality of the circumstances measuring if the driver acted with “reasonable safety” toward vehicles from the rear.
Though not explicit, there appears to be a “zone of danger” standard: if driver A wants to deviate/change lanes, and driver B is close enough behind such that driver B could be unsafely affected without fair warning from driver A, then driver A should first use a turn signal to alert driver B. Combined with other factors like sudden swerving or rapid decelerating, failing to signal could serve as proof of negligence, even recklessness, in both the civil and criminal contexts, if for example there is then an accident with property damage and/or personal injury.
Likewise, such combined conduct like swerving, decelerating, failing to use a turn signal – even if none of it was actually illegal – could all together provide police with reasonable suspicion to pull over the vehicle and conduct a warrantless investigatory seizure, and if there was probable cause, conduct a warrantless search of the vehicle and its occupants.7
This warrantless seizure and search could lead to serious consequences: an arrest, prosecution, conviction, and jail or prison sentence for serious crimes like serial OWI, or possession of a controlled substance, or carrying a concealed weapon.
Like other relatively minor traffic infractions such as rolling through a stop sign or driving with a burnt-out tail lamp that might warrant just an oral warning, failing to use a turn signal could open the door to much more grave legal consequences.
In isolation, though, the mere failure to use a turn signal to change lanes – most especially when there are no motorists anywhere close behind the deviating vehicle – should not be grounds to get seized, much less searched, by police.8
Law enforcement, prosecutors, and courts must be vigilant not to elide the requirements for deviating with those for turning; as discussed in the next section, there are different statutes for each, and only turning officially requires turn signals.9
Turns and Stops
In contrast to parallel/lateral moves like lane changes, perpendicular moves like turns (especially stop and turns) are potentially much more dangerous. As such, the law is more explicit about requiring turn signals when turning.
There are three rules depending on the location of the vehicle. First, if a vehicle intends to turn at an intersection, it must be the in proper position upon the roadway as required in Wis. State section 346.31 (specific rules for turns indicated by pavement markings; for right turns; for left turns and U-turns; and for left turns and U-turns on 3-lane highways).
Second, if a vehicle intends to enter a private road or driveway, it must be the in proper position upon the roadway as required in section 346.32 (mostly the same as in s. 346.31).
Third, if the vehicle intends to turn “from a direct course,” as with not clearly indicated lanes, then the driver must wait “until the movement can be made with reasonable safety.”10
Next, the substantive law on signaling while turning requires that when turning, “[i]n the event any other traffic may be affected by the movement, no person may turn any vehicle without giving an appropriate signal in the manner provided in section 346.35.
A person making a U-turn shall use the same signal used to indicate a left turn. When given by the operator of a vehicle other than a bicycle, electric scooter, or electric personal assistive mobility device, the signal shall be given continuously during not less than the last 100 feet traveled by the vehicle before turning.
The operator of a bicycle, electric scooter, or electric personal assistive mobility device shall give the signal continuously during not less than the last 50 feet traveled before turning. A signal by the hand and arm need not be given continuously if the hand is needed in the control or operation of the bicycle, electric scooter, or electric personal assistive mobility device.”11
A motorist can use the hand and arm in lieu of or in addition to signals by signal lamp, from the left side of the vehicle:
Left turn or U-turn – hand and arm extended horizontally.
Right turn – hand and arm extended upward.
Stop or decrease speed – hand and arm extended downward.12
Bicyclists can use either arm to signal.13 Also, drivers not on the highway, but about to enter it, are not “traffic which may be affected” by the change in lanes.14
The penalties for an unsafe turn/stop without a signal are the same as for an unsafe lane deviation: a forfeiture of not less than $20 nor more than $40 for the first offense and not less than $50 nor more than $100 for the 2nd or subsequent conviction within a year.15
Any operator of a bicycle, electric scooter, or electric personal assistive mobility device may be required to forfeit not more than $20.16
However, because section 346.34(1) is a safety statute, the violation is negligence per se.17 When it is impossible to signal for the last 100 feet before turning, though, the 100 feet requirement does not apply.18 In addition to the 100 feet rule, in calculating the time required to safely execute his maneuver, the driver must also consider the condition of the highway.19
As with lane deviations, the failure to properly signal can lead not just to civil liability for negligence, but possible criminal charges if there is an accident and/or injury. Likewise, in context, failing to signal could give police reasonable suspicion for a warrantless seizure, and then probable cause for a search.
Conclusion
In sum, even if not legally required, using a turn signal is more than just common courtesy to other drivers; it is also the safer course of action, for everyone involved – both to avoid an accident, with the possible civil and criminal liability; and also to avoid those flashing red-and-blue lights and a fishing expedition by the local curious constabulary.
Endnotes
1 Wis. Stat. §§ 346.13(1) and 346.34(1), respectively.
2 The statute also encompasses “those roadways divided into lanes by clearly indicated longitudinal joints.” (Different construction methods distinguish “longitudinal joints” from “transverse joints”; the former are parallel to the direction of the traffic flow. See, e.g., US DOT Federal Highway Administration Technical Advisory on Concrete Pavement Joint, January 2019. Available online at https://www.fhwa.dot.gov/pavement/ta504030.pdf pp. 2-3.)
3 Wis. Stat. § 346.13(1); see also Wis JI‑Civil 1355 Deviation from Traffic Lane: Clearly Indicated Lanes (2008).
4 Wis. Stat. § 346.34(1)(a)3. See also Wis JI‑Civil 1354 Turn or Movement: Ascertainment that Turn or Movement Can Be Made with Reasonable Safety: Lookout (7/2023), cited by Wis JI‑Civil 1355 Comment (“This instruction is to be given only when there are clearly indicated lanes. If lanes are not clearly indicated, the proper instruction is Wis JI‑Civil 1354. Committee Notes, 1957, 40 W.S.A. at 331.”)
5 Wis JI‑Civil 1350 Turn or Movement: Signal Required (2008)—Comment. See also the annotation Wis. Stat. § 346.13: “In calculating the time required to safely execute a deviation from a traffic lane or a turn at an intersection, a driver must consider the condition of the highway Thompson v. Howe, 77 Wis. 2d 441, 451, 253 N.W.2d 59, 63 (1977).” In that case, because of the icy road conditions, the supreme court held that driver was required to give a signal for 100 feet before changing lanes and for 100 feet after the lane change and before turning left.
6 Wis. Stat. § 346.17(1)
7 See, e.g., State v. Waldner, 206 Wis. 2d 51, 556 N.W.2d 681 (1996) (arresting officer had reasonable suspicion to warrant investigative stop, even though none of defendant’s actions was illegal).
Likewise, see In re Refusal of Anagnos, 2012 WI 64, ¶¶ 57-58, 341 Wis. 2d 576, 601, 815 N.W.2d 675, 687 (“Much like stopping at an uncontrolled intersection or weaving within a lane, executing a left turn over an elevated median that is more than five feet wide, though arguably not illegal, would encourage a reasonable officer to further monitor the driver. Anagnos’s subsequent actions, twice accelerating rapidly and executing a second left turn without signaling, could confirm to a reasonable officer that there was cause for suspicion. That suspicion would reasonably be heightened by the officer’s experience that he is more likely to encounter impaired drivers at 1:15 in the morning.”).
Eight Wisconsin OWI court of appeals cases that are unpublished but citable as persuasive involve, in varying fashions, drunk drivers who failed to properly use a turn signal. In all but one case (discussed in the next footnote), there was more suspicious conduct than simply not using a turn signal while changing lanes:
- enter the lane of the police squad car on a highway and almost hitting it
- while driving after sunset without headlights on, turn left twice onto downtown streets without signaling either time—the second time the officer had to brake
- turn twice without signaling, with the officer only two car lengths behind
- in addition to changing lanes while going through an intersection without signaling, drive with either dim or burnt out registration lamp and turn a corner too sharply, striking and going over the curb
- drift toward the center line, swerve, weave within its lane, and use the left turn signal to signal a right turn
- drift within the same lane of traffic and touching the line with both tires
- drift within the same lane of traffic and touching the line with both tires, and change lanes 2 or three times
8 See, e.g., Arizona v. Gant, 556 U.S. 332, 129 S.Ct. 1710, 173 L.Ed.2d 485 (2009).
9 In an outlier case (unpublished but citable as persuasive), the driver did not turn, but merely changed lanes twice without signaling—moved one lane over, and then moved back into the original lane (no indication of type of road, speed, road conditions, etc.). Citing Thompson v. Howe (discussed above), the appellate court noted that no driver may deviate lanes “until doing so could be done without endangering other vehicles approaching from the rear.” But there was no evidence that the driver endangered the officer; he did not testify that he had to brake or take any evasive or corrective action—he was 6-8 car lengths behind. With the average sedan being about 14 feet long, the driver was around 84-112 feet ahead. This decision strains credulity.
10 Wis. Stat. § 346.34(1)(a)3. See also Wis JI‑Civil 1354 and Wis JI‑Civil 1352 Turn: Position and Method When Not Otherwise Marked or Posted (2008).
11 Wis. Stat. § 346.34(1)(b). See also Wis JI‑Civil 1350.
12 Wis. Stat. § 346.35.
13 Id.
14 Donlea v. Carpenter, 21 Wis.2d 390, 124 N.W.2d 305 (1963). Though this case about yielding and right-of-ways analyzed the language of Wis. Stat. § 346.34(1), because the case discussed “changing lanes,” the same principle should also apply to deviating/lane changes.
15 Wis. Stat. § 346.36(1).
16 Wis. Stat. § 346.36(2).
17 Betchkal v. Willis, 127 Wis. 2d 177, 378 N.W.2d 684 (1985); Grana v. Summerford, 12 Wis.2d 517, 521, 107 N.W.2d 463 (1961). Wis JI‑Civil 1350.
18 Betchkal; Wis JI‑Civil 1350.
19 See Thompson v. Howe, 77 Wis. 2d 441, cited above. Because of the icy road conditions, the driver was required to give a signal for 100 feet before changing lanes and for 100 feet after the lane change and before turning left. Instead, though, the driver changed lanes, with a signal, about 30 to 40 feet from an intersection, in a curving maneuver, and then braked about 10 feet from the intersection. Because of icy roads, the other driver was not able to stop in time and rear-ended the first driver.
