Auto Adjust quality bit rate

[davebo]

I am hoping a Spotify employee can provide an answer. For automatic the app states the rate is adjusted if network connections are weak. I cannot find where the behavior of this setting is fully described.  My question is does the application select the highest quality when the network signal is good, or is there a maximum bit rate lower then Very High when Automatic is enabled?

My question applies to cellular streaming, but both can be answered.