This will probably never happen, but... There is technically already a partial solution for this but AFAIK there are no regulations or legal frameworks to allow it. Construction workers can already buy noise cancelling bluetooth headphones [1][2] so they can listen to music while working. They will still need ear plugs when working with loud tools but the headphones are loud. If the equipment with the beepers also transmitted a signal the headphones could be adapted to pick up via bluetooth along with a TDR calculation to figure out distance, the worker could hear the machine coming to them and would probably be more annoyed they can't hear their music. All of this also assumes that regulations were stricter on fencing off the area from non construction workers assuming you get rid of the beepers.

Missing is the standard for linking these headphones and the myriad of construction equipment to something that calculates distance and warns the listener. So there you go HN entrepreneurs. Write the RFC's, make some prototypes and give them for free to a construction company. Maybe partner with companies that produce the top 10 fork-lifts, skid-steers, tractors, bulldozers, flat-bed trucks and dump trucks as a start. BONUS if you give the workers a way to talk to the driver without having to allocate licensed frequencies.

[1] - https://www.homedepot.com/b/Safety-Equipment-Hearing-Protect...

[2] - https://www.lowes.com/pd/DEWALT-Earbud-Noise-Canceling-Headp...