re: Widening Highways Never Fixes Traffic. But Darnit, It Did in Texas

The rule shouldn't be taken to mean that it never improves traffic to build additional lanes. It just means that building an additional lane won't always solve traffic problems.

If there is too much volume for an existing roadway, I think it is beyond question that an additional lane will improve traffic flow. But if there are sufficient lanes to handle the volume, an additional lane may not improve traffic flow.

It really comes down to whether Uncle Bob is doing 45 in the left lane during rush hour. You can have the most efficient design, but if people aren't using it in an efficient way then it wont help a bit.