Install a fence around the yard that doesn't have any gaps in it. The solid structure is better for blocking the sound of traffic.
Plant a hedgerow by itself or in conjunction with the fence for an additional sound barrier between your home and the road. Plant additional shrubs near the home.
Install new windows with a higher sound transmission class (STC) rating than your current windows. The windows are often the area of the home where the sound enters, so new windows may make a large impact on the sound you hear inside. A door with more insulation is another way to reduce the sound.
Hang heavy drapes as an alternative way to counteract the traffic noise that enters through the windows.
Run a white noise machine in your home to help block some of the noise. Set up an indoor water fountain so the sound of the running water overpowers the traffic sounds.