WINNEBAGO COUNTY - A crash between a semi truck and a Winnebago County Highway Dept. truck sent two people to the hospital and backed up traffic on Hwy. 41.Sheriff's officials say the crash happened around 10:10 a.m. on Hwy. 41 northbound at Hwy. 26 in the Oshkosh area. The semi went into a work zone and hit a highway department truck from behind.Investigators say highway crews were doing shoulder work. The truck that was hit was holding a working, lighted sign that directed traffic to the left away from the work zone.The drivers of both trucks were taken to the hospital with non-life-threatening injuries. Both drivers were also talking to investigators.It was unclear how fast the semi was traveling, but sheriff's deputies say the truck did not appear to be speeding.The right lane of the highway was shut down for more than two hours after the crash. Backups stretched over three miles, according to the Department of Transportation.The highway crew's work on the shoulder was called off for the rest of the day.