Cologne (dpa / lnw) - A rear-end collision has led to a kilometer-long traffic jam on the busy Cologne ring road in the morning rush hour. On the A3 towards Oberhausen, according to initial police findings, a car drove into a truck between the Cologne-Mülheim and Leverkusen-Zentrum junctions on Wednesday and was thrown into the overtaking lane. To avoid a collision, another car swerved and collided with another car, a police spokesman said. Traffic was backed up just after 7 a.m. for eight kilometers.