I hate to be snarky, but there's another factor: laziness. When there's a replacement bridge under construction around here, business at the local dunkin donut

I hate to be snarky, but there's another factor: laziness. When there's a replacement bridge under construction around here, business at the local dunkin donuts goes up ALL DAY, not just at lunch and shift change. Everybody's there: laborers, supervisors, delivery drivers, managers, engineers, owners' reps from the state DOT and the towns involved. And, in Massachusetts we have a peculiar extra cost: The police force has a monopoly on doing the traffic safety work that flag people do everywhere else. They have the right to arrest people who work in or near roads if they start working without a paid police detail on the site, or keep working after the police detail leaves. Slows work down; gives people a reason to wait around after arriving on the job.