I am well aware of Verizon's planned locations for field trials of 5G broadband service in 2017 and their reasons for their choices. This message is to suggest - strongly - at least one other area. The reason is to provide a broadband service choice that is missing in this area.
I live in the Northern California East Bay - broadly including Oakland, Berkeley, Albany, Kensington, El Cerrito, Richmond, etc. - densely populated and poorly served by broadband providers. Notably, Verizon has no broadband capabilities in this area, cellular coverage is mediocre here and what is worse, and more relevant with respect to the 5G trials, is that the broadband market is dominated by one supplier - a cable company because of the absence of Verizon from this market. The only other choice offers much lower bandwidth (about 15 mbps of real thruput for download and much less for upload). We need an alternative and 5G seems to be a way to provide high bandwidth, wide coverage at relatively low capital expenditure for the addressable market. Further, in my experience, Verizon is a preferable provider compared to the incumbent.
From available information it is known that Verizon plans to deploy 5G in Sacramento, CA for trials and it would not be unreasonable to extend the trial to the East Bay where another set of geographical, technical, market and competitive issues could be examined without undue logistical issues.