After Dwight Eisenhower initiated the interstate highway system in the USA in the 1950s, there has been a steady effort to expand and "improve" it. In recent years, this has included adding highway lanes to "reduce" traffic problems. Click on the link below for a podcast that will help you understand the failure of this thinking in its stated goals and how other developed nations have done a better job in the planning of people movement in urban areas:
Why Do We Keep Widening Highways If It Doesn’t Reduce Traffic?