As thousands of drivers continued to return to Athens yesterday after the Easter break, they were informed they could soon face more traffic misery as improvement work is about to begin on the Corinth-Patras national road. More than a million cars are estimated to have left Athens in the buildup to the Easter weekend. Vacationers are expected to continue returning in dribs and drabs throughout this week but without the jams seen on Easter Monday, when a tailback at the Corinth toll post reached 7 kilometers. Drivers could witness similar scenes this summer as Olympia Odos, the private company responsible for managing the Corinth-Patras highway, said yesterday that a raft of roadworks on the highway would begin in the next couple of weeks. The works will begin at various points along the highway at the same time so that the company can meet its target to complete the Corinth-Pyrgos section in three years. Olympia Odos has yet to announce what diversions will be in place while the work is under way but said that it intends to do so in the next few days. Toward the end of May work will also begin to widen sections of the Corinth-Patras national road, which is also expected to add to congestion problems. The company also rejected claims that there were tailbacks at toll posts on Monday because some drivers were refusing to pay the toll. By law, if a queue at a toll post is longer than 3 kilometers, authorities are required to lift the barriers so that cars can pass through for free and congestion can be eased. Olympia Odos said that the toll at the Corinth Canal was opened three times and at Rio seven times in order to avoid massive tailbacks. It blamed the length of the queues on the unexpectedly high number of vehicles that were on the road.