Yes, they are. This happens to be my home - a duplex - and fronts on the parking area. I thought it a good place for receptacles.
For those who don't recognize it, the meter box is really an "all in one". That is, meter on top, lower half a main breaker as wellas the branch circuit breakers.
One of my first installs I nippled together two single bases. Oops. Got the Commonwealth Edison install book and learned they only allow multiple bases like these: