Probable cause found to support stop for unsafe lane deviation, § 346.13(1).
¶12 Here, DeNovi testified that, while traveling in a group of three vehicles, he observed Anderson’s vehicle drift into the outside lane for approximately 100 yards and then swerve back to the inside lane. Both lane deviations were made without signaling and the second was “drastic.” It was also raining on a winter night. We agree with the circuit court that, irrespective of whether Anderson’s actions adversely affected traffic, this evidence “leads to a reasonable inference that the driver was not paying attention to other drivers at all[,] including determining [whether] his vehicle movement was being safely made in view of the vehicles behind him.” DeNovi had probable cause to stop Anderson for an unsafe lane deviation.
¶13 Additionally, we agree with the State’s alternative argument that DeNovi had probable cause to stop Anderson for failing to signal, contrary toWis. Stat. § 346.34(1)(b). That statute requires motorists to signal whenever “any other traffic may be affected by the movement.” See Wis. Stat. § 346.34(1)(b). Here, given the proximity of the traffic, the bad weather, the darkness, and Anderson’s “drastic” lane change, we conclude Anderson was required, and failed, to signal his lane deviations. We reject Anderson’s argument that, because he did not adversely affect traffic, he did not need to signal. Under Wis. Stat.§ 346.34(1)(b), it is irrelevant that Anderson’s failure to signal ultimately had no adverse effect on traffic. The statute applies where traffic “may” be affected.