I looked up microtrenching and it looks like they're basically stopping traffic and pointing an angle grinder straight down. Directional boring machines are out there, why aren't we running a bunch of those 24/7? Do they need a lot of supervision?
While the range of directional trenching is limited, requiring regular access points, the bigger issue is setup. Surveys and tests need to be done to determine if the area is suitable for directional trenching, and it only works well in certain circumstances. It's definitely heavily used in telecom installation but not a panacea.
Microtrenching is extremely simple and fast, but so far I don't know that anyone has nailed durability. Google's Louisville install used microtrenching and was an absolute debacle with the sealant constantly failing and the cables ending up laying on the surface of the pavement. Google ended up shutting down service in Louisville and the cost of repairing the failed microtrenching may have been a big reason why. Certainly get them a lot of bad press and ill will from their customer base.
