That's a problem with your network provider, not LTE. Do you happen to be on an MVNO? The smaller providers rent a limited portion of bandwidth from the main carriers, once they get popular in your area the speeds will tank. That shouldn't happen on the main carriers unless they just suck were you live.
In Tokyo I was struggling to load google maps on Line Mobile (Softbank MVNO) as the speed fell to less than 0.5Mbps. Switched to Softbank and now get 30Mbps in the same scenario and an absurd 50 gig monthly limit (which doesn't count bandwidth used on various sites, like Youtube...)
I have Verizon LTE in a major US city. When I first got my iPhone 6 I was getting 30 mbps speeds (much better than my 1.5 on my iPhone 4s). Now unless I'm in EXACT spots I only get 5mpbs or so in most areas. It's gotten progressively slower for whatever reason despite paying for their most expense plan and being under the throttle limit.