We bought a home three houses from the main drag and after several days we didn't notice the traffic noise. You become use to it and it just fades into the background. We sit outside on our patio and it is very quiet. Everyone in the neighborhood says the same thing you get use to it.
First i would recommend looking into the windows. Masking the windows or installing sound barrier windows. Planting trees could break up the sound as well. Also maybe invest in a wall or barrier for the yard. The closer the barrier is to the highway the more proficient the sound will be decreased.
This is a good question, as the highway noise could easily ruin the environment that you are living in. One thing that I've found to work is to plant large, lush trees on the highway side of the house.
I lived in a house on a main highway for 14 years. Everyone told me I wouldn't like the noise but I learned to live with it and actually got to the point where I didn't notice it. Insulated drapes help a lot, as do trees. After I while, you don't hear it.