The stretch of I26 from Sandy Run down past Orangeburg to 95 is a disaster. It should have been six laned years ago. Just check Google maps and your almost always guaranteed to see an accident there by mid afternoon, esp on Sundays.
The reason in general is simple, the core of the Interstate system was constructed decades ago. Just think how many more cars are on the road now. Then realize that half are not looking at the road. We were on the way back from Asheville one weekend and I counted the cars as we/they passed. A solid 50%of the people were looking at their phone.
This is the one I notice the most because of the number of times I drive to Charleston. I also see wrecks on other stretches of I-26 around the intersection with 301 and I-95 and going towards Greenville/Spartanburg.
In my opinion, the cause is the volume of traffic on highways designed in the 1950s. People fail to observe even the most basic courtesies when driving. The left lane is for faster traffic but it is frequently occupied by people who just refuse to drive in the right lane. This causes people to pass on the right creating dangerous lane changes. Then there are people who insist on driving 85-90 and tailgate.
Another cause is the lack of a 3 axle only lane. Hard to do that when there are just 2 lanes, but trucks try to pass each other and it will sometimes take them a mile or more if the speed difference is just a couple MPH. The traffic then backs up behind them.
I-26 should be 6 lanes in both directions the entire way, but traffic rules have to be enforced. In October I drove back and forth to Charleston several times a week. One week I did not see a single SCDPS vehicle (highway patrol) either way. Without enforcement the law of the jungle prevails.
For example, I was in the left lane passing a large truck. I always leave a gap for safety between myself and the car in front of me. We were going a little over 70 and there was a lot of traffic. Just before I passed the truck a black SUV came up the right lane and shot the gap. He had to be going 90. The gap was probably 2 car lengths at the most. Dude had a death wish.
I have noticed that the highway patrol is making more use of unmarked cars, but it is not nearly enough. I actually saw a Honda Pilot with blue lights stopping a speeder on I-77 near Columbia. (Forest Drive exit) The number of traffic deaths will continue to go up if we don't step up enforcement.