congestion increases the closest you drive to CBD
Build a road from 290 at Cameron to Riverside at IH-35.
Parallel to IH-35, since that's where the worst congestion is. Widening IH-35 would not be very good, because too many lanes makes passing inefficient, and this is why additional lanes to IH-35 do not double the capacity of a road. I used to work at Wilbur Smith & Associates Engineering firm in Columbia, South Carolina, in the highway department, as a secretary. I learned there that it's most efficient to build a new road from where the congestion begins to where it ends, rather than widen an existing road, because passing in a wide road is not efficient. Passing in a two lane road is very efficient. Adding one lane to a one lane road nearly doubles its capacity, but adding third or fourth lanes to a double lane road is not efficient because passing is very inefficient. https://www.nytimes.com/1990/07/27/obituaries/wilbur-s-smith-78-a-designer-of-major-transportation-systems.html