INDIANAPOLIS (AP) — A group of truck drivers is suing Indiana's governor over a 35 percent fee increase placed on large trucks that use the Indiana Toll Road.

The Indianapolis Business Journal reports that the federal lawsuit that was filed Wednesday challenges the constitutionality of the fee hike and alleges that it's discriminatory and excessive. The lawsuit says that the truck drivers won't benefit from the hike because the revenue will be used for projects unrelated to the toll road.

A spokeswoman for Gov. Eric Holcomb says they don't believe there's a constitutional issue.

Holcomb in September announced that the toll road operator would increase tolls in exchange for $1 billion for state infrastructure improvements over the next several years. Indiana lawmakers later questioned the governor's tolling decision.

The 157-mile tollway crosses northern Indiana from Chicago to the Indiana-Ohio state line.