* Wrote:
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> I never realized new rail needed grinding. I
> assumed it left the plant with a finished shape.
> Maybe transit light rail vehicles need a smoother
> finish than freight?

Noise abatement (no squealing and scraping)seems to be the main reason (and of course, improving the life span of wheel sets from wear and tear on the rough rail), probably helps make the neighbors (aka the local voters...)a little happier...

We've come a long way since the days back when the folks at a certain agency who were ordering the LRV's, and the other folks who were building the tracks, didn't actually seem to understand the difference in rail/wheel profiles... And that agency had to "peal" away thousands of usable hours of life expectancy off of the wheelsets, on the brand new LRV's they'd just bought, so they wouldn't derail on the switch points of the brand new track they had just built, due to the "sharp flanges".