Michigan Senate Bill 582 goes into effect July 18. The new law amends the Michigan Vehicle Code to allow a truck tractor and lowboy trailer combination of any length to operate on a designated highway, subject to certain conditions.

The Code prescribes maximum lengths for different types of vehicles operating on designated highways.  ("Designated highway" means a highway approved by the Michigan Department of Transportation (MDOT) or a local authority with respect to a highway under its jurisdiction.)

The bill provides that, for a truck tractor and lowboy trailer combination on a designated highway, there would be no maximum length, if the lowboy trailer did not exceed 59 feet, except as otherwise permitted.  A lowboy trailer wheelbase could not exceed 55 feet as measured from the kingpin coupling to the center of the rear axle or the rear axle assembly. 

A lowboy trailer longer than 59 feet could not operate with more than four axles unless an oversized load permit were issued by MDOT or a local authority with respect to highways under its jurisdiction.

According to the Bill’s sponsors, “To the extent that the bill resulted in certain truck tractor and lowboy trailer combinations traveling on roads that are not designated  as ‘all season roads,’ there would be an indeterminate impact related to damage to State and local roads.

Click here to review the complete text of the Bill.