ION - Waterloo Region's Light Rail Transit

[Markster]

It's "Tactile paving"

https://en.wikipedia.org/wiki/Tactile_paving

Tactile warnings provide a distinctive surface pattern of truncated domes, cones or bars detectable by long cane or underfoot which are used to alert the visually impaired of approaching streets and hazardous surface or grade changes.

How they find those plates to know where to cross is beyond me.

These are only at places where there are curb-cuts with level access. Elsewhere, there are curbs with a detectable drop, so one can tell there is no crossing.  These indicate where the sidewalk ends, and also indicate a signaled/signed crossing.