$10 million seems excessive but as noted it's false to state this is a cosmetic improvement only. They need to do the work, and to do it right they will need time and time, when you are working with heavy equipment on a highway where you need to close lanes, means money. The materials they are using are probably the lowest cost line item on the budget.

Now, if you were complaining about whether the retaining wall blocks were a great idea 20 years ago, and whether they were designed with proper drainage of if anyone thought about the root systems of the bushes they planted and how that might come together to shorten the life of these walls, you would have a point. And I also get that the sunk cost fallacy doesn't mean we shouldn't examine the mistakes of the past, but that doesn't mean this is some kind of vanity project. These walls have been on an accelerated decay for the past 3-4 years and need some kind of repair/replacement just for safety's sake.