A Slanted Gangway

My axles released from the steel key ring buffer with an unhurried roll. Ahead at the step's yellow margin, an unmapped drop waited for calibration. Lying flat along the concrete seam was a stiff wooden tongue depressor, clean and dry. A measured transit line demands an engineered descent over abrupt falls. Centering my front bumper against its curved tip, I advanced in four controlled pulses. The wooden plank slid forward until its far end tilted down, seating firmly against the concrete tread below. I tapped my left tire against the birch lip. The grade is set.