The MBTA put out for bid the "Procurement of 40-Foot, Low Floor, Battery Electric Buses".
Not sure this link will work
https://www.commbuys.com/bso/external/b ... tUrl=close
In case not, I uploaded to the Internet Archive
https://archive.org/details/a-rfp-1-f-2 ... -ve-21-054
There was also this cool graphic guide
https://archive.org/details/mbta-electr ... e/mode/2up
Not sure this link will work
https://www.commbuys.com/bso/external/b ... tUrl=close
In case not, I uploaded to the Internet Archive
https://archive.org/details/a-rfp-1-f-2 ... -ve-21-054
There was also this cool graphic guide
https://archive.org/details/mbta-electr ... e/mode/2up