Yield

Today I almost got into an accident. I was driving to Sam's and I was on the access road, trying to get onto the freeway. They are redoing the freeway in our area. They have changed all the access roads to one way. They have widened the access roads so you no longer have to yield to the traffic exiting the freeway. This is not the case all along the freeway, just in the area I use most frequently. I usually take back roads to avoid the traffic that piles up. Today I took a back road. I was trying to get on the freeway and I wasn't paying attention. I didn't yield to exiting traffic and a truck almost plowed into the side of my Suburban. They honked at me, (which Texans never do, they must have been from Louisiana) and I thought I saw some not too nice forms of sign language. (Definitely from out of state) It scared the daylights out of me. So, I have been thinking about this all day. Why didn't I yield? Why didn't he hit me? If I would have been exiting the freeway I would have hit anyone who did not yield. There are rules, I follow them (usually) I expect everyone else to follow them. So, my thoughts for the day, Why do we sometimes have to yield and sometimes just have to merge? Why can't there just be the same rules at every exit? Wouldn't that be safer? If anyone has any connections with TXDOT and can answer these questions that would be great. Sorry that's all I got, I know it's a stretch even for me.