This view looks under three parked semi-trailers in an office park next to the Green River Trail. I placed myself in this position to see whether or not it would be possible to ride a trike under the trailers. I’m sure it would be possible if I were to remove the flag from my trike and tilt my head slightly to the side. On a later ride elsewhere I confirmed my belief: http://www.pbase.com/listorama/image/165713998 .
I shot this picture while sitting on my recumbent trike. My right foot is visible at bottom, resting on a trike pedal.