The blind spots around a commercial truck are commonly referred to as its "No-zone." While most people are aware that trucks have larger blind spots than cars, they might not realize exactly how large these blind spots are.
The blind spots of a commercial truck extend on all four sides. On the left side of a large truck, the blind spot extends from the cab's driver-side mirror across one lane of traffic. In the truck's rear, a truck driver cannot see you if you are within 30 feet of the back of its trailer. A general rule of thumb is that you should not drive close enough to a truck that you cannot see the driver's reflection in his or her side mirror.
Many motorists are unaware that trucks have blind spots in front of their vehicles. The front blind spot extends approximately 20 feet in front of the cab. This makes it important for you to give a truck plenty of room after passing before merging back into its lane. Finally, the blind spot on the truck's right is the largest and extends across two full lanes of traffic. You should never try to pass a tractor-trailer on the right.