The major obstacle preventing full New London service is the bridge over the Connecticut River between Old Saybrook and Old Lyme. The drawbridge section is closed for a certain period of time to allow trains to pass, which prevents large boats from passing under. The Marine Trades Association opposes additional service, which would mandate more bridge closings. The 2003 agreement with Amtrak limited weekday traffic over the bridge to 2 SLE and 39 Amtrak trains until 2018, although it was revised in 2010 and 2013. Since 2003, New London had been served by cross-honored Amtrak trains plus one or two dedicated SLE roundtrips.