OSWM logo OpenSidewalkMap ← Back to Hazard Analysis Map

Hazard Classification Guide

Ruleset version 0.1.0 · hash e92f5f0ebaaf33f5 · 29 rules · generated 2026-07-31 22:03 UTC
⚠ Screening tool — not a safety certification. These rules are provisional. A feature with no detected hazard is not certified safe. Missing data is never treated as evidence of absence. Severity levels, confidence scores and surface-material proxies require participatory calibration.
User Profiles

Each rule may affect one or more profiles differently:

🚶
Pedestrian
General walking comfort and safety.
♿
Wheelchair user
Continuous rollable access with manageable gradients.
🦯
Blind or low-vision pedestrian
Detectable, orientable and predictable transitions.
🧓
Older or reduced-mobility pedestrian
Stability, effort and fall-risk oriented assessment.
Severity Levels
LevelMeaning
0 — No detected hazardNo rule matched the available evidence.
1 — UncomfortableMay reduce comfort or require additional effort.
2 — UnfavorableMeaningfully degrades pedestrian accessibility.
3 — DangerousMay create a serious safety or mobility hazard.
4 — CriticalPotential barrier or extreme contextual safety risk.
Hazard Categories
IDLabelDescription
longitudinal_slopeLongitudinal slopeDirectional terrain or explicitly mapped incline.
cross_slopeCross slopeOnly explicit OSM incline:across evidence.
kerbKerb transitionKerb height/type and transition traversability.
tactile_orientationTactile and orientationTactile evidence and detectable material transitions.
surfaceSurfaceSmoothness plus provisional surface-material proxies.
barrierBarrierExplicit or strongly inferred traversal barriers.
Classification Rules
Filter by category / profile
Categories
Profiles
Jump to: Longitudinal slope · Cross slope · Kerb transition · Tactile and orientation · Surface · Barrier

Longitudinal slope

Directional terrain or explicitly mapped incline.

uphill_over_12_5 ⇅ directional80% confidence

Travel direction rises by more than 12.5%.

Condition: directional_incline_percent > 12.5
ProfileSeverityImpactTraversability
🚶 Pedestrian3 — DangerousExtreme climbing effortPassable
♿ Wheelchair user4 — CriticalIndependent ascent may be impossibleImpassable
🦯 Blind or low-vision pedestrian2 — UnfavorableExtreme climbing effortPassable
🧓 Older or reduced-mobility pedestrian4 — CriticalExtreme exertion and fall riskPassable with extreme risk
uphill_8_33_to_12_5 ⇅ directional80% confidence

Travel direction rises by more than 8.33% and at most 12.5%.

Condition: 8.33 < directional_incline_percent ≤ 12.5
ProfileSeverityImpactTraversability
🚶 Pedestrian2 — UnfavorableHigh climbing effortPassable
♿ Wheelchair user3 — DangerousVery difficult ascentPassable
🦯 Blind or low-vision pedestrian1 — UncomfortableHigh climbing effortPassable
🧓 Older or reduced-mobility pedestrian3 — DangerousHigh exertionPassable
uphill_5_to_8_33 ⇅ directional80% confidence

Travel direction rises by more than 5% and at most 8.33%.

Condition: 5 < directional_incline_percent ≤ 8.33
ProfileSeverityImpactTraversability
🚶 Pedestrian1 — UncomfortableIncreased climbing effortPassable
♿ Wheelchair user2 — UnfavorableDifficult ascentPassable
🧓 Older or reduced-mobility pedestrian2 — UnfavorableIncreased exertionPassable
downhill_over_12_5 ⇅ directional80% confidence

Travel direction descends by more than 12.5%.

Condition: directional_incline_percent < -12.5
ProfileSeverityImpactTraversability
🚶 Pedestrian3 — DangerousExtreme braking and fall riskPassable
♿ Wheelchair user4 — CriticalLoss-of-control riskPassable with extreme risk
🦯 Blind or low-vision pedestrian3 — DangerousExtreme descent hazardPassable
🧓 Older or reduced-mobility pedestrian4 — CriticalExtreme fall riskPassable with extreme risk
downhill_8_33_to_12_5 ⇅ directional80% confidence

Travel direction descends by more than 8.33% and at most 12.5%.

Condition: 8.33 < |directional_incline_percent| ≤ 12.5 (descent)
ProfileSeverityImpactTraversability
🚶 Pedestrian2 — UnfavorableHigh braking effortPassable
♿ Wheelchair user3 — DangerousSubstantial loss-of-control riskPassable
🦯 Blind or low-vision pedestrian2 — UnfavorableSteep descent hazardPassable
🧓 Older or reduced-mobility pedestrian3 — DangerousHigh fall riskPassable
downhill_5_to_8_33 ⇅ directional80% confidence

Travel direction descends by more than 5% and at most 8.33%.

Condition: 5 < |directional_incline_percent| ≤ 8.33 (descent)
ProfileSeverityImpactTraversability
🚶 Pedestrian1 — UncomfortableIncreased braking effortPassable
♿ Wheelchair user2 — UnfavorableDifficult controlled descentPassable
🦯 Blind or low-vision pedestrian1 — UncomfortableIncreased descent carePassable
🧓 Older or reduced-mobility pedestrian2 — UnfavorableIncreased fall riskPassable

Cross slope

Only explicit OSM incline:across evidence.

cross_slope_over_595% confidence

Explicit cross slope exceeds 5%.

Condition: |cross_slope_percent| > 5
ProfileSeverityImpactTraversability
🚶 Pedestrian2 — UnfavorableStrong lateral imbalancePassable
♿ Wheelchair user4 — CriticalHigh tip or drift riskPassable with extreme risk
🦯 Blind or low-vision pedestrian2 — UnfavorableStrong lateral imbalancePassable
🧓 Older or reduced-mobility pedestrian3 — DangerousHigh fall riskPassable
cross_slope_3_to_595% confidence

Explicit cross slope is greater than 3% and at most 5%.

Condition: 3 < |cross_slope_percent| ≤ 5
ProfileSeverityImpactTraversability
🚶 Pedestrian1 — UncomfortableLateral imbalancePassable
♿ Wheelchair user3 — DangerousSubstantial drift or tip riskPassable
🦯 Blind or low-vision pedestrian1 — UncomfortableLateral imbalancePassable
🧓 Older or reduced-mobility pedestrian2 — UnfavorableInstabilityPassable
cross_slope_2_to_395% confidence

Explicit cross slope is greater than 2% and at most 3%.

Condition: 2 < |cross_slope_percent| ≤ 3
ProfileSeverityImpactTraversability
♿ Wheelchair user2 — UnfavorableNoticeable lateral effortPassable
🧓 Older or reduced-mobility pedestrian1 — UncomfortableMild lateral instabilityPassable

Kerb transition

Kerb height/type and transition traversability.

kerb_raised90% confidence

A raised kerb is associated with the crossing.

Condition: associated_kerbs contains raised · applies to: crossing
ProfileSeverityImpactTraversability
🚶 Pedestrian1 — UncomfortableAbrupt level changePassable
♿ Wheelchair user4 — CriticalKerb blocks independent passageImpassable
🧓 Older or reduced-mobility pedestrian3 — DangerousTrip and fall hazardPassable
kerb_ambiguous_yes70% confidence

A kerb is mapped without a traversable kerb type.

Condition: associated_kerbs contains yes · applies to: crossing
ProfileSeverityImpactTraversability
♿ Wheelchair user3 — DangerousKerb traversability uncertainPassable
🧓 Older or reduced-mobility pedestrian2 — UnfavorablePotential abrupt level changePassable
kerb_rolled85% confidence

A rolled kerb can still require substantial effort.

Condition: associated_kerbs contains rolled · applies to: crossing
ProfileSeverityImpactTraversability
♿ Wheelchair user2 — UnfavorableDifficult rolling transitionPassable
🦯 Blind or low-vision pedestrian1 — UncomfortableWeakly defined transitionPassable
🧓 Older or reduced-mobility pedestrian2 — UnfavorableUnstable transitionPassable

Tactile and orientation

Tactile evidence and detectable material transitions.

flush_without_tactile95% confidence

A flush kerb is explicitly paired with absent tactile paving.

Condition: associated_transition_states has pair: kerb=flush, tactile_paving=no · applies to: crossing
ProfileSeverityImpactTraversability
🦯 Blind or low-vision pedestrian4 — CriticalStreet boundary may be undetectablePassable with extreme risk
🧓 Older or reduced-mobility pedestrian1 — UncomfortableTransition lacks tactile cuePassable
lowered_without_tactile90% confidence

A lowered kerb is explicitly paired with absent tactile paving.

Condition: associated_transition_states has pair: kerb=lowered, tactile_paving=no · applies to: crossing
ProfileSeverityImpactTraversability
🦯 Blind or low-vision pedestrian3 — DangerousStreet boundary has weak tactile detectionPassable
crossing_tactile_no90% confidence

Tactile paving is explicitly absent at the crossing.

Condition: associated_tactile_paving contains no · applies to: crossing
ProfileSeverityImpactTraversability
🦯 Blind or low-vision pedestrian3 — DangerousNo mapped tactile warning at street transitionPassable
uniform_transition_surface45% confidence

Crossing, kerb and adjacent sidewalk share one explicitly mapped surface; this is a low-confidence detectability proxy.

Condition: uniform_transition_surface = True · applies to: crossing
ProfileSeverityImpactTraversability
🦯 Blind or low-vision pedestrian3 — DangerousMaterial transition may be difficult to detectPassable

Surface

Smoothness plus provisional surface-material proxies.

smoothness_very_horrible90% confidence

Very horrible smoothness indicates an extreme unevenness.

Condition: smoothness = very_horrible
ProfileSeverityImpactTraversability
🚶 Pedestrian3 — DangerousExtreme unevennessPassable
♿ Wheelchair user4 — CriticalIndependent rolling may be impossibleImpassable
🦯 Blind or low-vision pedestrian3 — DangerousSevere trip and orientation hazardPassable
🧓 Older or reduced-mobility pedestrian4 — CriticalExtreme fall riskPassable with extreme risk
smoothness_horrible90% confidence

Horrible smoothness indicates severe unevenness.

Condition: smoothness = horrible
ProfileSeverityImpactTraversability
🚶 Pedestrian2 — UnfavorableSevere unevennessPassable
♿ Wheelchair user4 — CriticalRolling may be effectively blockedImpassable
🦯 Blind or low-vision pedestrian3 — DangerousSevere trip hazardPassable
🧓 Older or reduced-mobility pedestrian3 — DangerousHigh fall riskPassable
smoothness_very_bad90% confidence

Very bad smoothness creates substantial mobility difficulty.

Condition: smoothness = very_bad
ProfileSeverityImpactTraversability
🚶 Pedestrian2 — UnfavorableSubstantial unevennessPassable
♿ Wheelchair user3 — DangerousVery difficult rolling surfacePassable
🦯 Blind or low-vision pedestrian2 — UnfavorableSubstantial trip hazardPassable
🧓 Older or reduced-mobility pedestrian3 — DangerousHigh instabilityPassable
smoothness_bad90% confidence

Bad smoothness creates a meaningful mobility penalty.

Condition: smoothness = bad
ProfileSeverityImpactTraversability
🚶 Pedestrian1 — UncomfortableUneven walking surfacePassable
♿ Wheelchair user2 — UnfavorableDifficult rolling surfacePassable
🦯 Blind or low-vision pedestrian2 — UnfavorableTrip hazardPassable
🧓 Older or reduced-mobility pedestrian2 — UnfavorableInstability and fall riskPassable
surface_sand55% confidence

Surface material is a provisional mobility proxy.

Condition: surface = sand
ProfileSeverityImpactTraversability
🚶 Pedestrian2 — UnfavorableLoose surfacePassable
♿ Wheelchair user4 — CriticalWheels may become immobilizedImpassable
🦯 Blind or low-vision pedestrian2 — UnfavorableUnstable surfacePassable
🧓 Older or reduced-mobility pedestrian3 — DangerousHigh instabilityPassable
surface_grass55% confidence

Surface material is a provisional mobility proxy.

Condition: surface = grass
ProfileSeverityImpactTraversability
🚶 Pedestrian1 — UncomfortableVariable natural surfacePassable
♿ Wheelchair user3 — DangerousHigh rolling resistancePassable
🦯 Blind or low-vision pedestrian1 — UncomfortableVariable surfacePassable
🧓 Older or reduced-mobility pedestrian2 — UnfavorableUnstable footingPassable
surface_ground_earth_dirt55% confidence

Surface material is a provisional mobility proxy.

Condition: surface ∈ {ground, earth, dirt, unpaved}
ProfileSeverityImpactTraversability
🚶 Pedestrian1 — UncomfortableWeather-sensitive surfacePassable
♿ Wheelchair user3 — DangerousHigh or variable rolling resistancePassable
🦯 Blind or low-vision pedestrian1 — UncomfortableIrregular surfacePassable
🧓 Older or reduced-mobility pedestrian2 — UnfavorableUnstable footingPassable
surface_gravel55% confidence

Surface material is a provisional mobility proxy.

Condition: surface = gravel
ProfileSeverityImpactTraversability
🚶 Pedestrian1 — UncomfortableLoose aggregatePassable
♿ Wheelchair user3 — DangerousDifficult rolling surfacePassable
🦯 Blind or low-vision pedestrian1 — UncomfortableLoose aggregatePassable
🧓 Older or reduced-mobility pedestrian2 — UnfavorableUnstable footingPassable
surface_cobble_sett55% confidence

Surface material is a provisional mobility proxy.

Condition: surface ∈ {cobblestone, unhewn_cobblestone, sett}
ProfileSeverityImpactTraversability
🚶 Pedestrian1 — UncomfortableUneven jointsPassable
♿ Wheelchair user3 — DangerousDifficult vibration-heavy rollingPassable
🦯 Blind or low-vision pedestrian2 — UnfavorableIrregular trip-prone surfacePassable
🧓 Older or reduced-mobility pedestrian2 — UnfavorableTrip and instability hazardPassable
surface_compacted_fine_gravel50% confidence

Surface material is a provisional mobility proxy.

Condition: surface ∈ {compacted, fine_gravel}
ProfileSeverityImpactTraversability
♿ Wheelchair user2 — UnfavorableIncreased rolling resistancePassable
🧓 Older or reduced-mobility pedestrian1 — UncomfortablePotentially loose footingPassable

Barrier

Explicit or strongly inferred traversal barriers.

barrier_steps95% confidence

Steps interrupt step-free movement.

Condition: highway = steps
ProfileSeverityImpactTraversability
🚶 Pedestrian1 — UncomfortableAdditional effortPassable
♿ Wheelchair user4 — CriticalStep-free passage blockedImpassable
🦯 Blind or low-vision pedestrian2 — UnfavorableLevel change requires carePassable
🧓 Older or reduced-mobility pedestrian3 — DangerousHigh effort and fall riskPassable
barrier_wheelchair_no95% confidence

OSM explicitly marks wheelchair access as unavailable.

Condition: wheelchair = no
ProfileSeverityImpactTraversability
♿ Wheelchair user4 — CriticalWheelchair access explicitly blockedImpassable
surface_impassable95% confidence

OSM explicitly describes the surface as impassable.

Condition: smoothness = impassable
ProfileSeverityImpactTraversability
🚶 Pedestrian4 — CriticalPassage explicitly impassableImpassable
♿ Wheelchair user4 — CriticalPassage explicitly impassableImpassable
🦯 Blind or low-vision pedestrian4 — CriticalPassage explicitly impassableImpassable
🧓 Older or reduced-mobility pedestrian4 — CriticalPassage explicitly impassableImpassable
OSWM Hazard Analysis Classification Guide · auto-generated from hazard_analysis/rules.py · source