California has a lower speed limit of 55 mph for trucks: https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=VEH&sectionNum=22406 https:

California has a lower speed limit of 55 mph for trucks: https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=VEH&sectionNum=22406 https://leginfo.legislature.ca.gov/faces/codes_displaySectio... This means that they generally stay in the rightmost lane, as slower traffic is supposed to keep right.