The Highway Patrol is reminding motorists to be careful as they enjoy the July 4th holiday. Motorists who slow down and travel at posted speeds will not only increase their chances of arriving at their destination safely they will also conserve fuel.  There will be an increased presence of troopers on the interstates and major four lane highways.  Speed is the leading cause of traffic collisions and fatalities in the state. Troopers will be cracking down on speeders during the holiday and will be using LIDAR and other speed timing devices to assist them in enforcing the speed laws.  Troopers will increase patrols on all interstates and major four lane highways during the holiday. Last year in North Carolina, 10 people died and 436 were injured over the July 4th holiday period.