They do have an incentive to avoid 4hour queues in people getting to work - at least when those queues mean companies start moving to other cities because of the traffic.
That's why cities are forever building new freeways, widening freeways, building bridges etc.
The cities don't get blamed for pileups in the same way that airports don't get blamed for plane crashes.
what is the incentive for highway planners? Isn't how many companies are in the area a little indirect of an incentive? How does it impact their individual wellbeing?
An indirect political incentive is a very weak incentive. There is more direct incentive to do nothing innovative.
That's why cities are forever building new freeways, widening freeways, building bridges etc.
The cities don't get blamed for pileups in the same way that airports don't get blamed for plane crashes.