A lot of these "cost" reports include money that couldn't be shifted around. E.g. they often include the salaries of people who worked on the project, and you

A lot of these "cost" reports include money that couldn't be shifted around. E.g. they often include the salaries of people who worked on the project, and you can't just not pay them and re-allocate those funds elsewhere. I'm also cynically skeptical that the money would go to road safety or healthcare or some other noble cause if it wasn't spent here. It seems more likely that the money would have stayed with whatever branch of government spent it, and instead it would've been used to buy a new tank or patrol cars or some such. Or in true Catch-22 fashion, they'd spend $3.5 million on a report on how to spend the remaining $500k but the report runs over budget and costs the full $4 million.