A large crowd of people walk, casually, across an elevated road or bridge.
There are people walking outside.
walking is another form of walk. If they walk across an elevated road or bridge, that would be outside.
exists e1 s1 s2 s3 x1 x2 x3.(across(e1,x3) & (n_road(x3) | n_bridge(x3)) & a_elevated(s3) & Theme(s3,x3) & a_casually(s2) & Manner(e1,s2) & Actor(e1,x1) & v_walk(e1) & of(x1,x2) & n_people(x2) & n_crowd(x1) & a_large(s1) & Theme(s1,x1))
exists p1 x1 e1 s1 x2 x3.((x1 = x2) & a_outside(s1) & Manner(e1,s1) & Actor(e1,x3) & v_walk(e1) & (x2 = x3) & n_people(x2))