One of the most frequent factors behind collisions is the "jackrabbit" driver. He's the guy who's constantly changing speeds, changing lanes, tailgating, and otherwise not fitting into traffic. Other often interrelated causes of traffic collisions are "disparate" vehicle speeds (when one driver is driving much faster than others), impatience, and frequent lane changes.
If you observe traffic way out in front of you, you can visualize what the "flow" of traffic is, as a whole. Visualize traffic as a single, giant organism, like a river. There will be vehicles within the overall picture (or flow) that are traveling faster, and some slower, but you can see what the overall pace of traffic is.
You may be surprised to know that the actual pace of traffic is not that much faster than the speed limit. One of the principles engineers use when setting a speed limit is to consider what speed a normal, reasonable driver actually drives on that particular stretch. Try to match your speed to the overall flow (without exceeding the speed limit by more than a few miles per hour). That said, you must be willing to accept the fact that traveling faster than a posted limit puts you at risk for a citation. But usually, if you are within just a few miles per hour of a speed limit, officers will not bother you, with some obvious exceptions like school zones and construction areas where a posted limit is viewed as an absolute.
Practice my "tortoise" style of driving! Pick your lane, and stay in it. Bopping and weaving from one lane to another, trying to pass every car on the road doesn't gain you much, and every single lane change you make increases your risk of collision. As I commute each day, I know which lane is the best for travel under normal circumstances. This may be the lane that I know becomes my exit ramp 5 miles up the road, or it may simply be the lane that flows better most of the time. Often, I choose on the basis of safety. On my motorcycle, for example, I ride in the far right lane (at a slower speed) or in the "car pool lane" for its faster flow, and the "escape" path afforded by the left (or right) shoulder. (In my state, it is legal for motorcycles to use the car pool lanes).
Relax, resist the urge to make frequent lane changes, use the two-second rule, and stay alert to the dangers posed by the jack rabbits around you! If someone needs to merge into the lane, back off a bit and let them in smoothly. In doing this, you are not only maintaining the flow, but you also set an example that others will follow. When you refuse to allow another driver to merge, the person behind you does the same thing. When you act courteously, the driver behind you ALSO will, and that helps keep traffic moving. I've seen repeatedly how discourtesy causes many of the bottlenecks that gridlock traffic every day.
Practice my "tortoise" style of driving, and, nine times out of ten, you will arrive at your destination just as quickly as the "jackrabbit." You will also not be nearly as stressed by the trip, whether it is a commute to work on Monday a.m., or a road trip to Shangri-La!
Keep the shiny side up!