The speed drops from 40 mph that exists between Roslyn Road and Locust Lane down to 30 mph on the same LIE Eastbound Service Road, between Locust Lane and Glen Cove Rd. Then the speed goes back to 40 mph east of Glen Cove Rd. The distance from Locust Lane to Glen Cove Rd. is only about 1/2 mile. It is very easy not to notice the 30 mph Speed Limit on that short 1/2 mile section of the Eastbound LIE Service Road. A police car can be on grass between the Exit 39 OFF RAMP of the LIE and the Eastbound Service Road even though the view from that location can be limited. Usage of LASER, rather than Radar facing Westward is being used, even though I believe LASER requires a direct line of sight to the target and the target can be near 1000 feet or 1/5 of a mile and the curvature of the road and grass/tree can also limit the use of LASER, but LASER has been used.