T-Mobile appears complicit in stating 'coverage' where none is physically possible, and has been confirmed by their engineers.
They've gone so far as to consider themselves as the ONLY carrier with LTE in this area, while it has none.
Sadly, their engineers will acknowledge the lack of service, but T-Mobile ERT and management will not.
This complete area is a 'No Service' zone but T-Mobile seems addicted to the MS-Paint 'bucket-fill' function.
This is highly disturbing as many areas w/o service where its expected (and roaming not-allowed) ends up with people out of coverage. This is a major highway in SoCal 2 miles from the freeway.