NAHANT – The speed on the Nahant Causeway has been reduced to 25 mph effective immediately.Nahant Police Lt. Thomas Hutton said the new speed limit is posted.Prior to the change, the speed limit was 35 mph on the Causeway entrance and exit and 45 mph in the center of the roadway.Hutton said it was necessary to reduce the speed limit due to the Causeway reconstruction project.”The Causeway is a construction zone,” Hutton said. “The speed limit is for the safety of the general public as well as the safety of the construction workers and police officers doing details. It is a dramatic change and one we want all area residents to be aware of.”Hutton added the speed limit would be strictly enforced and fines for speeding in a work zone are hefty.”Fines double in a work zone,” he said. “If someone is driving 10 miles over the speed limit in a work zone the fine would be $200 and they would be subject to insurance surcharges as well. We’re asking drivers to bear with us, slow down and enjoy the scenery.”The $20 million construction project got under way last month. The seven-phase project is expected to take three years to complete. According to the DCR, after Labor Day two lanes of traffic would be re-routed through the Nahant Beach Reservation parking lot.The second phase of the construction project is expected to get under way in the fall and continue through spring 2011. Phase 2 includes repairing the seawall, removing the existing light poles on the harbor side of the Causeway, drainage and reconstruction of the southbound travel lanes.Hutton said the new speed limit is expected to be in effect for the duration of the construction project.