Research — Illustrative (draft, unvalidated)

One corner, eight checks

A wheelchair rolls one street corner, drawn to scale in plan with the ramp profile beneath it. It stops and flashes at the first failing check among eight: the sidewalk, the pole in the route, the ramp count, the curb ramp, the warning surface, the crossing signal and the pushbutton. Play eight short stories, or switch to free play and pick exported stops, or drag the pole toward the route.

Mode

Story plays a prepared change and its fix. Free play is yours: every control snaps to an exported stop, and each control reads its own table.

Story

Geometry: illustrativev1 draft, unvalidated harness

Plan · one corner, drawn to scale in feet; the wheelchair stops at the first failing check

Profile along the route · the ramp from the walk down to the street, same x axis as the plan

Free play · pick a stop, or drag the pole on the plan

Each strip is a control: its stops are the exported values, and the colour under each stop is the exported verdict for that stop with the other inputs held where you left them. The checks are independent, so a control changes only the readings of its own table. Nothing between two stops exists in the file. The island-and-button case exists only in the crossing story, because the crosswalk table has no refuge axis.

Check being read · click a card or a table row to look at it on the corner

Actual

Required

Margin

How the harness read it

    All eight checks at this step · the failing row the chair stopped at is highlighted

    The chair stops at the first failing check in walk order, else at the check the step points at. There is deliberately no single corner verdict.

    Every check · first, middle and last step of this story

    The three columns are the first, middle and last steps the data marks for this story, labelled with their own step names. "Not measured" means the survey has not reached the dimension, never a pass. The "info" tag on a curb-ramp cell marks a result the harness reports as not applicable because of the ramp-length exception; it is an open question, not a pass.

    Precomputed results:every verdict, required value and margin on this page was computed by the real Python harness at export time and is played back from a data file. The page runs no harness logic and holds no standards tables, and it never interpolates between exported values. Not a live API call. The ada-harness is a v1 draft: no ADA consultant or accessibility specialist has reviewed it, and nothing here is a compliance determination. Every verdict, required value, margin, citation and reasoning line was computed by calling those functions at export time (harness commit a3895f4, through a thin composite that only maps one set of measurements onto the eight functions) and is played back from a data file. The corner is a generic illustration, not any real corner: every geometry input and everything drawn is illustrative. The pole is the exporter's model, a single post with an intrusion. The pushbutton card merges two harness functions because the pushbutton rule delegates reach to the operable-parts rule. The warning-surface step in which the surface is left out is the demo's own logic, not a harness result, and is tagged as such.Real functions this maps to:check_corner, check_sidewalk_slope, check_protruding_objects, check_curb_ramp_placement, check_curb_ramp, check_dws_scoping, check_detectable_warning, check_crosswalk, check_pedestrian_pushbutton, check_operable_parts.Not modeled: alterations and technical-infeasibility cases, shared use paths, other crossing types (mid-block, roundabout, slip lane), accessible pedestrian signal details beyond reach and location, bus stops, parking, and any real site. The ramp-length exception and the dome-height tolerance are open questions in the harness, reproduced below.See also:One corner, auto · Curb ramp (single check) · Detectable warning surface (single check)