and I thought it was just me......actually I think its just me.

Seattle is about to get devoured by a huge drilling machine
to make a tunnel for the new highway 99, the old was a
concrete viaduct that is crumbling and not earthquake
worthy. These huge drilling machines have been "very
active" for atleast the last 40 years drilling tunnels from
coast to coast. Read some place about high-speed train
tunnels already in place between NY and LA. The public
arent the passengers and I dont know who could be the
riders...probly riders that have passed many clearance
levels. The underground (literally) is being mapped out
and developed much like the surface. Could be one of
many reasons to hear a "hum".