There is a lot of featherbedding going on. Read this article about the Manhattan tunnel costs. https://www.nytimes.com/2017/12/28/nyregion/new-york-subway-... There are people who are paid to do nothing because that job existed in the past.

A lot of times in those instances the guys are only there for the peak hours or when the site is active. The light lets them leave the site with only the single lane open and not require overnight staffing.

Some of the reasons are:

- When the site is active they often have a need to hold traffic or otherwise alter the traffic pattern to move equipment around. An excavator swinging an arm through the travel lane, loading a dump truck with debris that might fly around a bit, etc.

- The two guys are more efficient than the portable light at moving traffic volumes, since they can extend/shorten cycles as they see fit, and don't have to add in a big extra margin for the last, slowest possible vehicle to get through the work zone. They can see when it's cleared and let traffic through the other direction immediately.