Merging when you are on the highway is one of the number one causes of traffic accidents on major highways and roadways. Too often, I have seen near misses on highways where someone is trying to merge but the other lane of traffic will not let them in. Merging into traffic is almost like watching a dance. You have to get the steps down just right in order not to step on anyone's toes and ruin the dance move.
The thing to remember about merging is that when you are actively trying to merge into traffic on a highway, the people who are already traveling in a straight path on the highway have the right of way. Before you actually get onto the highway, depending on what kind of a highway you are trying to merge onto, there may be a stoplight or a sign indicating that you need to increase your speed to whatever the current speed is on the highway. This is all done in an effort to prevent unnecessary accidents from occurring.
When you are getting ready to merge, it is important to look over your shoulder and gauge where the next car is behind you. Be prepared to step on the gas and really crank it up in order to successfully accelerate to whatever the current speed is that is being traveled by most of the vehicles on the highway. If you are not quick enough or if you try to merge onto the highway without accelerating to the proper speed, then you run the risk of actually causing an accident. For instance, imagine that you are already on the highway and you are traveling in the far right lane. Suddenly a car tries to merge right in front of you. The current speed that is being traveled by most of the cars on the highway is roughly 70 miles per hour. However, the car that has unexpectedly merged in front of you is traveling at a speed of 50 miles per hour. As a result, you have to slam on your brakes hard, which causes the person behind you to have to slam on their brakes hard. If someone isn't paying attention behind you, they might end up rear ending you or trying to perform a last minute maneuver in order to get out of the way, thereby causing another accident in a different lane of traffic.
It is important to remember to keep your distance (even more so) on a highway versus a residential street. For residential driving, you are supposed to maintain at least two car lengths behind the person in front of you (which people seldom do). However, when you are on a highway, you are almost always traveling at a much higher rate of speed, which means that you need to increase your stopping time between you and the person in front of you. Therefore, you should adjust your distance to approximately four to five car lengths since it would hypothetically take you longer to stop in the event that the person in front of you were to slow down.