In general, on freeways with at least two lanes of traffic in each direction, the left lane is the passing lane. Sometimes, however, semi-trucks drive in the left lane, making it difficult for other vehicles to pass, and frustrating those who are driving behind the semi-truck.
There are rules regarding whether a semi-truck driver can drive in the left lane, although these rules vary by state and even by city. In Missouri, semi-trucks cannot use the left lane on interstate highways, freeways or expressways in urban areas that have at least three lanes of traffic. This applies to vehicles used in the transportation of goods weighing over 48,000 pounds, freight vehicles and vehicles that carry eight passengers or more, except for vanpools and shuttle buses.
Truckers may be tempted to drive in the left lane, so that they do not disrupt traffic when it is merging onto the freeway from on-ramps. However, semi-trucks often travel slower than other vehicles on the freeway, so having one remain in the left lane when it is not necessary to do so could impact another motorists' ability to drive safely. This is because vehicles in the left lane that are driving slowly may cause other vehicles to weave in and out of other lanes of traffic, which could lead to a commercial truck accident.
No one wants to be in an accident with a semi-truck. These accidents can be catastrophic, as a fully-loaded semi-truck can cause serious damage on a smaller automobile and the occupants inside, who could be seriously injured or even killed. Those involved in commercial vehicle accidents will want to explore their legal options for compensation, which could be used to cover medical expenses, lost wages and other damages suffered in the crash.