How to set heuristic underpass ceiling height

[Ylannl]

• Ravi: add detected terrain height in streetlidar height estimation to postgres table
• Gina: look at lidar data height estimation and plot histogram to find representative minimum (table: extended_geometries_july)
• use the found minimum value for heuristic height
  • optionally: also look at size of building or underpass type to adjust heuristic height.
• Ravi: if underpass ceiling intersects with roof: do not model it

[balazsdukai]

Here’s a structured summary of Dutch regulations on the minimal inner height for underpasses, passthroughs (onderdoorgangen), viaducts, tunnels, and similar architectural elements in public
spaces, based on authoritative sources:

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📏 Key Standards for Minimal Inner Height in the Netherlands

1. General Road Infrastructure (CROW & European Norms)

• Standard minimal inner height for new construction:
  4.60 meters for underpasses, viaducts, and tunnels on public roads (including highways).

  • Source: CROW Handboek Wegontwerp (Dutch road design manual) and European norms (4.50 m base + 0.10 m Dutch safety margin).
  • Context: This applies to the vertical profile of free space (vrij profiel van vrije ruimte), ensuring clearance for standard vehicles (e.g., trucks up to 4.0 m height).
  • Reference: CROW Kennisbank (snippets: "Europese normen schrijven een
    verticaal profiel van vrije ruimte voor van 4,50 meter. Voor de Nederlandse situatie is hier een overlagingsmarge van 0,10 meter aan toegevoegd").

• Marking requirements:

  • < 4.20 m: The underside of structures must be marked with 0.15 m wide white vertical stripes on a black background (RVV 1990, Reglement Verkeersregels en Verkeerstekens).
  • ≤ 4.00 m: Prohibition signs (C19) are required for heights ≤ 4.00 m (e.g., "Gesloten voor voertuigen hoger dan X meter").
  • 4.00–4.60 m: Informational signs (L1) are used to indicate the actual height (e.g., "Vrije doorrijhoogte: 4.30 m").
  • Reference: Wegenwiki, CROW.

• Older infrastructure:

  • Minimum height of 4.50 m is the current standard for new builds (older structures may have lower clearances, e.g., 3.90 m).
  • Reference: Wegenforum ("De 4.50 meter is de minimum hoogte die tegenwoordig bij nieuwbouw wordt aangehouden").

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2. Highways (Autosnelwegen)

• Standard clearance: 4.60 meters (common for Dutch highways).
  • Reference: Joost de Vree ("In Nederland is voor snelwegen als doorrijhoogte 4,6 m gebruikelijk").

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3. Pedestrian/Cycle Underpasses & Public Space

• Bouwbesluit 2012 (Dutch Building Decree):

  • Bridges with underpasses > 1 m height: Require railing height of at least 1.00 m (1.20 m if the bridge is ≥ 13 m above ground).
  • Reference: IPV Delft ("op elke brug met een onderdoorgang van meer dan een meter was een leuning van 1,0 meter hoog nodig").

• Local regulations:

  • Municipalities may impose additional rules (e.g., Lelystad specifies galerijen/arcades for shop overhangs).
  • Design standards: Must comply with NEN norms, CROW guidelines, Bouwbesluit, and CUR recommendations.
  • Reference: Lokale Regelgeving.

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4. Industrial/Logistics (Vrachtwagens & Overkappingen)

• Truck access:
  • Signage mandatory for heights < 6.00 m (industrial sites).
  • Recommended minimal height: 2.4–2.6 meters for car/van access (e.g., private driveways, carports).
  • Reference: Maessen Tentsupply ("Signalering en waarschuwingsborden zijn verplicht wanneer de
    doorrijhoogte lager is dan 6 meter").

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📌 Summary Table of Minimal Heights

Structure Type	Minimal Inner Height	Regulation/Source	Notes
Highways (snelwegen)	4.60 m	CROW, European norms + Dutch margin	New construction standard.
Public roads (underpasses)	4.50–4.60 m	RVV 1990, CROW	4.50 m base + 0.10 m safety margin.
Marking required	< 4.20 m	RVV 1990 (C19/L1 signs)	White stripes on black background.
Prohibition signs (C19)	≤ 4.00 m	RVV 1990	For heights ≤ 4.00 m.
Informational signs (L1)	4.00–4.60 m	RVV 1990	Indicates actual height (e.g., 4.30 m).
Pedestrian/cycle underpasses	≥ 2.50 m*	Bouwbesluit 2012, local rules	*Varies by municipality.
Industrial truck access	≥ 6.00 m (signage)	Veiligheidsnormen	Signage mandatory below 6.00 m.
Private carports/overkappingen	2.4–2.6 m	Practical recommendation	For SUVs/cars.

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🔍 Key References

1. CROW Handboek Wegontwerp: Doorrijhoogte
2. RVV 1990 (Reglement Verkeersregels en Verkeerstekens): Official Text
3. Wegenwiki: Doorrijhoogte
4. Bouwbesluit 2012: IPV Delft Analysis
5. Local Regulations: Lokale Wet- en Regelgeving

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⚠️ Important Notes

• New vs. Existing: The 4.60 m standard applies to new construction; older structures may have lower clearances (e.g., 3.90–4.50 m).
• Municipal Variations: Always check local regulations (e.g., Amsterdam, Rotterdam) for additional requirements.
• Signage Rules:
  • C19: Prohibition (height ≤ 4.00 m).
  • L1: Information (4.00–4.60 m).
  • Marking: Mandatory for heights < 4.20 m (white stripes).

[Ylannl]

Plot from the amsterdam streetlidar estimation:

Nothing under 2m because this is a hard cap atm in the estimation script. The 22 below -2 meters is bit odd so I'll investigate.

[Ylannl]

Something else: maybe we should take into account small errors in the terrain elevation estimate (which affect the computed height here).