Two cars and a taxi were involved in an accident at the site of the controversial Causeway Bay flyover road rerouting yesterday. The accident, just before 10am, coincided with the first day that police were expected to clamp down on traffic violations at the site following a week-long grace period for motorists to adapt to changes. Police said the cars collided in the east-bound lane of Gloucester Road, near the Noon Day Gun, when one braked suddenly to avoid a vehicle in front that had slowed to change lanes. Two vehicles directly behind the braking car - a taxi and a second car - were unable to come to a halt quickly enough. No one was hurt and the vehicles were quickly moved off the road, a police spokesman said. It was a week yesterday since work began on the $73 million rebuilding of the flyover linking traffic from Wan Chai and the Cross Harbour Tunnel to Gloucester Road. Even though large signs warn drivers of the new traffic arrangement, the rerouting to permit the construction work has caused congestion and confusion among many motorists who have found themselves in the wrong lane.