"""Human-editable pedestrian hazard policy. These rules are deliberately provisional. Severity is not a probability and must never be interpreted as proof that an unflagged feature is safe. """ from __future__ import annotations HAZARD_RULESET_VERSION = "0.1.0" SEVERITY_LEVELS = { 0: { "label": "No detected hazard", "description": "No rule matched the available evidence.", "color": "#ffffff", }, 1: { "label": "Uncomfortable", "color": "#fee08b", "description": "May reduce comfort or require additional effort.", }, 2: { "label": "Unfavorable", "color": "#fdae61", "description": "Meaningfully degrades pedestrian accessibility.", }, 3: { "label": "Dangerous", "color": "#f46d43", "description": "May create a serious safety or mobility hazard.", }, 4: { "label": "Critical", "color": "#a50026", "description": "Potential barrier or extreme contextual safety risk.", }, } HAZARD_CATEGORIES = { "longitudinal_slope": { "label": "Longitudinal slope", "description": "Directional terrain or explicitly mapped incline.", }, "cross_slope": { "label": "Cross slope", "description": "Only explicit OSM incline:across evidence.", }, "kerb": { "label": "Kerb transition", "description": "Kerb height/type and transition traversability.", }, "tactile_orientation": { "label": "Tactile and orientation", "description": "Tactile evidence and detectable material transitions.", }, "surface": { "label": "Surface", "description": "Smoothness plus provisional surface-material proxies.", }, "barrier": { "label": "Barrier", "description": "Explicit or strongly inferred traversal barriers.", }, } HAZARD_PROFILES = { "pedestrian": { "label": "Pedestrian", "description": "General walking comfort and safety.", }, "wheelchair": { "label": "Wheelchair user", "description": "Continuous rollable access with manageable gradients.", }, "blind": { "label": "Blind or low-vision pedestrian", "description": "Detectable, orientable and predictable transitions.", }, "elderly": { "label": "Older or reduced-mobility pedestrian", "description": "Stability, effort and fall-risk oriented assessment.", }, } def _effect( severity: int, impact: str, traversability: str = "passable", ) -> dict[str, object]: return { "severity": severity, "impact": impact, "traversability": traversability, } HAZARD_RULES = [ { "id": "barrier_steps", "category": "barrier", "description": "Steps interrupt step-free movement.", "confidence": 95, "condition": {"field": "highway", "operator": "equals", "value": "steps"}, "effects": { "pedestrian": _effect(1, "Additional effort"), "wheelchair": _effect(4, "Step-free passage blocked", "impassable"), "blind": _effect(2, "Level change requires care"), "elderly": _effect(3, "High effort and fall risk"), }, }, { "id": "barrier_wheelchair_no", "category": "barrier", "description": "OSM explicitly marks wheelchair access as unavailable.", "confidence": 95, "condition": {"field": "wheelchair", "operator": "equals", "value": "no"}, "effects": { "wheelchair": _effect(4, "Wheelchair access explicitly blocked", "impassable") }, }, { "id": "surface_impassable", "category": "barrier", "description": "OSM explicitly describes the surface as impassable.", "confidence": 95, "condition": { "field": "smoothness", "operator": "equals", "value": "impassable", }, "effects": { "pedestrian": _effect(4, "Passage explicitly impassable", "impassable"), "wheelchair": _effect(4, "Passage explicitly impassable", "impassable"), "blind": _effect(4, "Passage explicitly impassable", "impassable"), "elderly": _effect(4, "Passage explicitly impassable", "impassable"), }, }, { "id": "kerb_raised", "category": "kerb", "description": "A raised kerb is associated with the crossing.", "confidence": 90, "applies_to": ["crossing"], "condition": { "field": "associated_kerbs", "operator": "contains", "value": "raised", }, "effects": { "pedestrian": _effect(1, "Abrupt level change"), "wheelchair": _effect(4, "Kerb blocks independent passage", "impassable"), "elderly": _effect(3, "Trip and fall hazard"), }, }, { "id": "kerb_ambiguous_yes", "category": "kerb", "description": "A kerb is mapped without a traversable kerb type.", "confidence": 70, "applies_to": ["crossing"], "condition": { "field": "associated_kerbs", "operator": "contains", "value": "yes", }, "effects": { "wheelchair": _effect(3, "Kerb traversability uncertain"), "elderly": _effect(2, "Potential abrupt level change"), }, }, { "id": "kerb_rolled", "category": "kerb", "description": "A rolled kerb can still require substantial effort.", "confidence": 85, "applies_to": ["crossing"], "condition": { "field": "associated_kerbs", "operator": "contains", "value": "rolled", }, "effects": { "wheelchair": _effect(2, "Difficult rolling transition"), "blind": _effect(1, "Weakly defined transition"), "elderly": _effect(2, "Unstable transition"), }, }, { "id": "flush_without_tactile", "category": "tactile_orientation", "description": "A flush kerb is explicitly paired with absent tactile paving.", "confidence": 95, "applies_to": ["crossing"], "condition": { "field": "associated_transition_states", "operator": "transition_pair", "kerb": "flush", "tactile_paving": "no", }, "effects": { "blind": _effect( 4, "Street boundary may be undetectable", "passable_with_extreme_risk", ), "elderly": _effect(1, "Transition lacks tactile cue"), }, }, { "id": "lowered_without_tactile", "category": "tactile_orientation", "description": "A lowered kerb is explicitly paired with absent tactile paving.", "confidence": 90, "applies_to": ["crossing"], "condition": { "field": "associated_transition_states", "operator": "transition_pair", "kerb": "lowered", "tactile_paving": "no", }, "effects": { "blind": _effect(3, "Street boundary has weak tactile detection"), }, }, { "id": "crossing_tactile_no", "category": "tactile_orientation", "description": "Tactile paving is explicitly absent at the crossing.", "confidence": 90, "applies_to": ["crossing"], "condition": { "field": "associated_tactile_paving", "operator": "contains", "value": "no", }, "effects": { "blind": _effect(3, "No mapped tactile warning at street transition"), }, }, { "id": "uniform_transition_surface", "category": "tactile_orientation", "description": ( "Crossing, kerb and adjacent sidewalk share one explicitly mapped " "surface; this is a low-confidence detectability proxy." ), "confidence": 45, "applies_to": ["crossing"], "condition": { "field": "uniform_transition_surface", "operator": "equals", "value": True, }, "effects": { "blind": _effect(3, "Material transition may be difficult to detect"), }, }, { "id": "smoothness_very_horrible", "category": "surface", "description": "Very horrible smoothness indicates an extreme unevenness.", "confidence": 90, "condition": { "field": "smoothness", "operator": "equals", "value": "very_horrible", }, "effects": { "pedestrian": _effect(3, "Extreme unevenness"), "wheelchair": _effect(4, "Independent rolling may be impossible", "impassable"), "blind": _effect(3, "Severe trip and orientation hazard"), "elderly": _effect(4, "Extreme fall risk", "passable_with_extreme_risk"), }, }, { "id": "smoothness_horrible", "category": "surface", "description": "Horrible smoothness indicates severe unevenness.", "confidence": 90, "condition": { "field": "smoothness", "operator": "equals", "value": "horrible", }, "effects": { "pedestrian": _effect(2, "Severe unevenness"), "wheelchair": _effect(4, "Rolling may be effectively blocked", "impassable"), "blind": _effect(3, "Severe trip hazard"), "elderly": _effect(3, "High fall risk"), }, }, { "id": "smoothness_very_bad", "category": "surface", "description": "Very bad smoothness creates substantial mobility difficulty.", "confidence": 90, "condition": { "field": "smoothness", "operator": "equals", "value": "very_bad", }, "effects": { "pedestrian": _effect(2, "Substantial unevenness"), "wheelchair": _effect(3, "Very difficult rolling surface"), "blind": _effect(2, "Substantial trip hazard"), "elderly": _effect(3, "High instability"), }, }, { "id": "smoothness_bad", "category": "surface", "description": "Bad smoothness creates a meaningful mobility penalty.", "confidence": 90, "condition": { "field": "smoothness", "operator": "equals", "value": "bad", }, "effects": { "pedestrian": _effect(1, "Uneven walking surface"), "wheelchair": _effect(2, "Difficult rolling surface"), "blind": _effect(2, "Trip hazard"), "elderly": _effect(2, "Instability and fall risk"), }, }, { "id": "surface_sand", "category": "surface", "description": "Surface material is a provisional mobility proxy.", "confidence": 55, "condition": {"field": "surface", "operator": "equals", "value": "sand"}, "effects": { "pedestrian": _effect(2, "Loose surface"), "wheelchair": _effect(4, "Wheels may become immobilized", "impassable"), "blind": _effect(2, "Unstable surface"), "elderly": _effect(3, "High instability"), }, }, { "id": "surface_grass", "category": "surface", "description": "Surface material is a provisional mobility proxy.", "confidence": 55, "condition": {"field": "surface", "operator": "equals", "value": "grass"}, "effects": { "pedestrian": _effect(1, "Variable natural surface"), "wheelchair": _effect(3, "High rolling resistance"), "blind": _effect(1, "Variable surface"), "elderly": _effect(2, "Unstable footing"), }, }, { "id": "surface_ground_earth_dirt", "category": "surface", "description": "Surface material is a provisional mobility proxy.", "confidence": 55, "condition": { "field": "surface", "operator": "in", "value": ["ground", "earth", "dirt", "unpaved"], }, "effects": { "pedestrian": _effect(1, "Weather-sensitive surface"), "wheelchair": _effect(3, "High or variable rolling resistance"), "blind": _effect(1, "Irregular surface"), "elderly": _effect(2, "Unstable footing"), }, }, { "id": "surface_gravel", "category": "surface", "description": "Surface material is a provisional mobility proxy.", "confidence": 55, "condition": {"field": "surface", "operator": "equals", "value": "gravel"}, "effects": { "pedestrian": _effect(1, "Loose aggregate"), "wheelchair": _effect(3, "Difficult rolling surface"), "blind": _effect(1, "Loose aggregate"), "elderly": _effect(2, "Unstable footing"), }, }, { "id": "surface_cobble_sett", "category": "surface", "description": "Surface material is a provisional mobility proxy.", "confidence": 55, "condition": { "field": "surface", "operator": "in", "value": ["cobblestone", "unhewn_cobblestone", "sett"], }, "effects": { "pedestrian": _effect(1, "Uneven joints"), "wheelchair": _effect(3, "Difficult vibration-heavy rolling"), "blind": _effect(2, "Irregular trip-prone surface"), "elderly": _effect(2, "Trip and instability hazard"), }, }, { "id": "surface_compacted_fine_gravel", "category": "surface", "description": "Surface material is a provisional mobility proxy.", "confidence": 50, "condition": { "field": "surface", "operator": "in", "value": ["compacted", "fine_gravel"], }, "effects": { "wheelchair": _effect(2, "Increased rolling resistance"), "elderly": _effect(1, "Potentially loose footing"), }, }, { "id": "cross_slope_over_5", "category": "cross_slope", "description": "Explicit cross slope exceeds 5%.", "confidence": 95, "condition": { "field": "cross_slope_percent", "operator": "abs_gt", "value": 5, }, "effects": { "pedestrian": _effect(2, "Strong lateral imbalance"), "wheelchair": _effect(4, "High tip or drift risk", "passable_with_extreme_risk"), "blind": _effect(2, "Strong lateral imbalance"), "elderly": _effect(3, "High fall risk"), }, }, { "id": "cross_slope_3_to_5", "category": "cross_slope", "description": "Explicit cross slope is greater than 3% and at most 5%.", "confidence": 95, "condition": { "field": "cross_slope_percent", "operator": "abs_range", "min_exclusive": 3, "max_inclusive": 5, }, "effects": { "pedestrian": _effect(1, "Lateral imbalance"), "wheelchair": _effect(3, "Substantial drift or tip risk"), "blind": _effect(1, "Lateral imbalance"), "elderly": _effect(2, "Instability"), }, }, { "id": "cross_slope_2_to_3", "category": "cross_slope", "description": "Explicit cross slope is greater than 2% and at most 3%.", "confidence": 95, "condition": { "field": "cross_slope_percent", "operator": "abs_range", "min_exclusive": 2, "max_inclusive": 3, }, "effects": { "wheelchair": _effect(2, "Noticeable lateral effort"), "elderly": _effect(1, "Mild lateral instability"), }, }, { "id": "uphill_over_12_5", "category": "longitudinal_slope", "description": "Travel direction rises by more than 12.5%.", "confidence": 80, "directional": True, "condition": { "field": "directional_incline_percent", "operator": "gt", "value": 12.5, }, "effects": { "pedestrian": _effect(3, "Extreme climbing effort"), "wheelchair": _effect(4, "Independent ascent may be impossible", "impassable"), "blind": _effect(2, "Extreme climbing effort"), "elderly": _effect(4, "Extreme exertion and fall risk", "passable_with_extreme_risk"), }, }, { "id": "uphill_8_33_to_12_5", "category": "longitudinal_slope", "description": "Travel direction rises by more than 8.33% and at most 12.5%.", "confidence": 80, "directional": True, "condition": { "field": "directional_incline_percent", "operator": "range", "min_exclusive": 8.33, "max_inclusive": 12.5, }, "effects": { "pedestrian": _effect(2, "High climbing effort"), "wheelchair": _effect(3, "Very difficult ascent"), "blind": _effect(1, "High climbing effort"), "elderly": _effect(3, "High exertion"), }, }, { "id": "uphill_5_to_8_33", "category": "longitudinal_slope", "description": "Travel direction rises by more than 5% and at most 8.33%.", "confidence": 80, "directional": True, "condition": { "field": "directional_incline_percent", "operator": "range", "min_exclusive": 5, "max_inclusive": 8.33, }, "effects": { "pedestrian": _effect(1, "Increased climbing effort"), "wheelchair": _effect(2, "Difficult ascent"), "elderly": _effect(2, "Increased exertion"), }, }, { "id": "downhill_over_12_5", "category": "longitudinal_slope", "description": "Travel direction descends by more than 12.5%.", "confidence": 80, "directional": True, "condition": { "field": "directional_incline_percent", "operator": "lt", "value": -12.5, }, "effects": { "pedestrian": _effect(3, "Extreme braking and fall risk"), "wheelchair": _effect(4, "Loss-of-control risk", "passable_with_extreme_risk"), "blind": _effect(3, "Extreme descent hazard"), "elderly": _effect(4, "Extreme fall risk", "passable_with_extreme_risk"), }, }, { "id": "downhill_8_33_to_12_5", "category": "longitudinal_slope", "description": "Travel direction descends by more than 8.33% and at most 12.5%.", "confidence": 80, "directional": True, "condition": { "field": "directional_incline_percent", "operator": "negative_range", "min_abs_exclusive": 8.33, "max_abs_inclusive": 12.5, }, "effects": { "pedestrian": _effect(2, "High braking effort"), "wheelchair": _effect(3, "Substantial loss-of-control risk"), "blind": _effect(2, "Steep descent hazard"), "elderly": _effect(3, "High fall risk"), }, }, { "id": "downhill_5_to_8_33", "category": "longitudinal_slope", "description": "Travel direction descends by more than 5% and at most 8.33%.", "confidence": 80, "directional": True, "condition": { "field": "directional_incline_percent", "operator": "negative_range", "min_abs_exclusive": 5, "max_abs_inclusive": 8.33, }, "effects": { "pedestrian": _effect(1, "Increased braking effort"), "wheelchair": _effect(2, "Difficult controlled descent"), "blind": _effect(1, "Increased descent care"), "elderly": _effect(2, "Increased fall risk"), }, }, ]