As a over the road trucker,How do I determine the state I worked in?

[TomD8]

As an OTR trucker, your income is subject to state income tax only in your home state (your state of residence).  It is not subject to income tax in states you pass through on the road.

The only exception might be if you physically worked at a location in a non-resident state. 

Drivers who are intrastate drivers, drive within the 100 mile radius of their terminal (in a non-resident state) or who are not subject to DOT hours of service, may be taxed by the work state and the resident state.

[Granite]

I don’t believe that’s correct. Your premises of living in one state and driving in another almost never exist. Sometimes a 100 mile radius of your home could include 3 other states, and pickups and deliveries are not considered working in those states. Most drivers local regional or OTR will cross state lines and work in several states, IE pickup and deliver, that shouldn’t require that they be taxed in the surrounding states because as you put it, they worked there. By your premise someone that works out of Philadelphia and pics up and delivers in NJ, DE, MD, VA, and NY, would have to pay taxes in all of those states because they worked there.

[TomD8]

(b)(1) No part of the compensation paid by a motor carrier providing transportation subject to the jurisdiction of the Commission under subchapter II of chapter 105 of this title or by a motor private carrier to an employee who performs regularly assigned duties in 2 or more States as such an employee with respect to a motor vehicle shall be subject to the income tax laws of any State or subdivision of that State, other than the State or subdivision thereof of the employee's residence.   https://www.govinfo.gov/content/pkg/STATUTE-104/pdf/STATUTE-104-Pg295.pdf