The google maps times seem to be set based on the more casual recreational or commuting cyclist. Mine says it would take 1 hour, 48 minutes, covering 18.9 miles. My actual distance this morning was 18.97 which I covered in under 73 minutes. My norm is closer to 83 minute for that distance, but still far shy of the 108 minutes Google wants it to take me.

I pass plenty of folks for whom those estimates would be accurate. And plenty pass me who would scoff if I posted my estimated times. Unlike cars which, regardless of their performance potential, all go pretty much the same speed because of road conditions, bike speeds are determined far more by their rider. The google times may be accurate for you, or may not.