The I-285 loop can be brutal during rush hour. Especially, as I've said on another thread, in the southwest corner (by the airport) during rush hour.
A larger beltway is needed. Namely, one that does make it too far away. A lot of people, if given the option of 80 miles or 120 miles (regardless of traffic congestion) will take the 80 mile option.
That's the big problem with loops.
But, it's better to build the bigger loop before it's needed. Once you need it, the land is more expensive, the route becomes more confined, and the overall hassle of building it becomes worse.
Sykotyk