Ind. Code § 8-17-5-5

Sec. 5. The county highway engineer shall work under the direction of the county executive and shall, under IC 5-4-1, give bond for the faithful performance of the engineer's duties. The county highway engineer may not enter into agreements to provide engineering services for pay to other local governmental units. However, an engineer may enter into contracts to provide engineering services for pay with the county executives of any two (2) or more counties, acting jointly. The county highway engineer may perform, at the direction of the executive, highway engineering work for municipalities within the county.