[Vermont Lt]

I remember my dad riding the trains as postal clerk. He carried a pistol. I thought that was cool.

Then he spent a few years sorting mail in a bus-like truck. It was akin to the rail cars, but on a bus platform.

[Vigilanteman]

I didn't know about the mail sorting busses until I toured the postal museum near Union Station in DC some years ago. They connected both towns not served by railroad lines as well as some of the lower traffic railroad lines.

Partly, but not totally a measure to address the decline of regular railroad service caused by union featherbedding.