Iron Bowl, originally from Singapore, explains why he's in favor of keeping police in charge of directing traffic around street construction:

... Police details is what makes Massachusetts roads so safe. As many people know, there are a lot of MASSHOLES in Massachusetts, and having a police cruiser, and a police officer, definitely helps slow traffic, making it less dangerous for the workers.

In Singapore, I've seen untrained construction workers try to control traffic, Though the Singapore drivers are much more tamed, it is very likely to see drivers ignore these road workers and cause a massive traffic jam or accident.

Directing traffic is not as easy as it seems. Even in a bright orange vest, I personally have many close encounters with cars almost hitting me while I'm helping with traffic control at an accident scene. ...

Only Massachusetts requires police details at road work sites. Boston drivers are from Massachusetts. Coincidence? DrivingLikeAss.Com thinks not.
The new DLA Labs study, Traffic Authority Figures & Their Effectiveness in the Modification of Ass-like Driving Behavior: A DLA Research Study, points to a possible sensory cortex dysfunction among Boston drivers. On the other hand, it could also be that they just like driving like ass.