Texas DPS and at times members of the Fort Bend County Sheriff and Precint 4 sit by the merging lanes to catch speeders on the tollroad bridges or the frontage roads. Many of the police shoot Ka radar bands to detect your speed. I have seen them have up to 3 cars per bound lane getting pulled over by one state trooper in each bound lane. A lot of people go flying 80+ Mph in speed zones ranging from 60-65 mph. The speed limit is real inconsistent as it changes every 3/4 to 1 mile throughout the Grand Parkway. Watch your surroundings constantly also as DPS and other law enforcement agencies can just sneak upon you and pull you over when least expect it.