# ADA Trip-Hazard Threshold Dataset

**Version / date checked:** 2026-07-24  
**Publisher:** Rockford Concrete Leveling Research  
**Record count:** 68

Rockford Concrete Leveling Research is the independent research and reference section of rockfordconcreteleveling.net.

## What the dataset contains

This documentary dataset joins the federal ADA change-in-level dimensions, context-specific zero-change rules, PROWAG dimensions and adoption status, selected municipal repair and program criteria, the current Illinois Accessibility Code, scoped Rockford and Winnebago County findings, OSHA's non-numerical general-industry rule, and published Illinois de minimis decisions.

It is structured to prevent a physical number from being quoted without the context that determines what the number means. Every row carries the instrument, section, application, legal force, party bound, instrument date, source URL, verification tier, date checked, and a limitation note where needed.

## Verification tiers

- **★** Read in an enacted code, regulation, standard, court opinion, or the issuing body's direct technical or inspection criteria.
- **●** Read in the issuing body's own program, FAQ, project, or document-review source; fully verified at that source but not represented as an enacted numerical rule.

Neither tier means that a particular property is covered or noncompliant. Tier describes source form, not legal outcome.

## Field dictionary

| Field | Meaning |
|---|---|
| `record_id` | Stable identifier for one rule, criterion, adoption event, holding, or scoped source finding |
| `dataset` | Federal, applicability, workplace, PROWAG, adoption, municipal, Illinois code, local, or case-law group |
| `jurisdiction_or_issuer` | Government body, court, standards body, or jurisdiction that issued the source |
| `instrument` | Name of the standard, regulation, code, rule, program, plan, or case |
| `section` | Section, paragraph, or record locator |
| `threshold_in` | Threshold in inches as a value, range, boundary, conflict, or blank when the rule is non-numerical |
| `threshold_mm` | Millimeter equivalent or source value |
| `treatment_required` | Required treatment, published program response, or court outcome |
| `max_slope_ratio` | Source ratio where applicable |
| `max_slope_percent` | Source or calculated percent where applicable |
| `applies_to` | Surface, facility, project, program, or factual context |
| `legal_force` | Regulation, standard, guideline, code, program criterion, precedent, or scoped finding |
| `binding_on` | Entity or context bound by the instrument |
| `instrument_date` | Publication, effective, revision, decision, or project date |
| `verification_tier` | ★ or ● as defined above |
| `source_url` | Direct official source URL |
| `date_checked` | Date the record was checked for this version |
| `limitation_note` | Boundary, conflict, scope, or interpretation warning |

## Processing rules

1. Dimensions are retained in inches and millimeters where the source supplies or supports both.
2. Ratios are retained as ratios. Percentages are explanatory calculations unless the source states them directly.
3. Exactly 0.25 inch is assigned to the vertical band because ADA §303.2 and PROWAG R302.6.2 expressly permit 0.25 inch maximum vertically.
4. A court's fact-specific measurement is not recoded as a statewide legal threshold.
5. A city program criterion is not recoded as an ordinance unless the source is an ordinance.
6. A project-specific code list is not recoded as a countywide rule.
7. Conflicting measurements or wording remain visible in the same record.

## Limitations

This is a documentary research dataset, not an accessibility inspection, legal opinion, repair specification, or certification of any property. “Trip hazard” is the query addressed by the page; the ADA technical provisions use “change in level.” Coverage depends on the governing law, entity, project, scoping provision, facility, and facts.

The municipal rows are a deliberately small source set containing different instrument types. They do not estimate a national average or distribution. Illinois de minimis decisions are fact-specific, and the Illinois Supreme Court states that there is no mathematical formula or bright-line test. No field measurements were performed.

## Files

- `ada-trip-hazard-thresholds-2026-07-24.csv` — flat row-level data for spreadsheets and analysis.
- `ada-trip-hazard-thresholds-2026-07-24.json` — metadata, methodology, tiers, limitations, fields, and all records.
- `ada-trip-hazard-thresholds-2026-07-24-sha256.txt` — SHA-256 checksums for the versioned files.

## Change log

| Version | Date | Change |
|---|---|---|
| 1.0 | 2026-07-24 | Initial verified publication. |