My driveway angles at a sharp angle to an infrequently used road such
that I almost never have to even look to see if there's traffic (because
there's only traffic about once a month at the time I'm entering the
road).

Still, that's not a safety margin so I have to stop all the time (of
course).

One thing a friend suggested is making a reflective roadside mirror out
of 'something'.

Have you guys any ideas to bump me to the next stage on this idea of
adding a mirror at the end of my driveway to see traffic (and, I guess,
for the traffic to see me)?