First you
must measure how many decibel of attenuation you need. For this you need a
sound level meter: If you don't have one at hand, a microphone + PC sound card +
Audacity can be used as well (many apps for Android/Ipad are also available for this). Measure two sound spectra at your location: the first one with traffic noise present, the second one when you feel that background noise level is comfortable for you. The difference between the two spectra will tell you how much attenuation you need, and which frequencies need to be attenuated more.
Next compare the attenuation offered by each possible solutions (noise attenuationg windows, wall insulation, etc.) against the attenuation you need to achieve. If it isn't enough, move away, otherwise try installing the best solution you can afford.
Noise should be stopped
before it enters the walls of your home: Once it is there, it can follow unsuspected paths to reach your ears (pipes, wall joints, etc.). The best way to stop it is to increase the
acoustic impedance of external walls and windows.
Attenuation could be increased using viscoelastic materials like rubber: however they are best for attenuating high frequencies.