primarily, the miller highway consisted of six lanes, supported above the street level on steel columns, which were located at regular intervals (~80 feet) at the outer edges and center of the roadway. longitudinal strength girders ran between the support columns along the direction of the roadway. the longitudinal girders supported the industrial looking balustrades and the median. lateral strength girders ran between the support columns across the roadway, and was the location of the expansion joints. smaller longitudinal and transverse floorbeams formed a lattice structure between major girders to support the road deck. the road deck consisted of reinforced concrete, on top of which the paved surface would sit. originally this was belgian block, and was eventually substituted or paved over with asphalt as construction materials matured. drainage was provided at the expansion joints (on the older sections) or grated channels along the edge of the road (newest sections), with rainwater and snowmelt being plumbed to the street through scuppers and downspouts located at the main support columns. it was not uncommon during the life of the highway that it would be supporting not only traffic, but 6 to 8 inches of standing water. the high impermeable balustrades, the undersized scuppers, and the lack of drain cleaning / maintenance were all ingredients which contributed to the structure's demise.