Add additional vehicle entrance dimensions

[Robbendebiene]

[!NOTE]
This proposal is part of a series of proposals focusing on accessibility around vehicle types. It is motivated by the development of a NeTEx based vehicle registry as well as the German handbook of accessible travel chains. We are happy to contribute the necessary XSD changes via a pull request on approval.

Rationale

The calculation of the vertical (δν+/-) and horizontal (δh) gap between vehicle and platform (as defined in EN 16586-1:2017 chapter 3.7) requires multiple different measurements. These also include dimensions of the equipment proposed in #873.

Knowledge about the vertical gap is especially important for wheelchair users. Level access potentially allows them to board and alight without aid, while none level access requires additional equipment like a ramp. Based on the vertical gap the incline/decline of the ramp can also be calculated. Knowledge about the horizontal gap is of equal relevance as larger gaps have to be bridged with ramps, gap fillers or foldable steps.

Use cases

• Accessibility (routing + passenger information)
• Mind the gap (passenger information)

The features are part of the German handbook of public transport accessibility from the DELFI association (see DEFLI 3100 and DELFI 3090).

Status quo

The PRM TSI chapter 2.5.10. summarises how both gaps should be calculated:

• The horizontal gap δh shall be calculated according to EN 15273-1:2013, Annex H1
• The vertical gap δv should be calculated considering:
  • nominal platform height according to TSI INF: 2013 point 4.2.9.2
  • nominal vehicle entrance height above track according to the vehicle construction drawing with design mass as defined in EN 15663:2009 (see also point 6.2.3.2 of the PRM TSI)
  • zero track cant

NeTEx properties related to the vertical gap:

• VehicleType and AccessVehicleEquipment have BoardingHeight which describes the height of the lowest step of the vehicle's entrance.
• DeckEntrance has a property called HeightFromGround which is vaguely defined as Height of ENTRANCE from ground.It might be identical to BoardingHeight, but it might also describe the height of the bottom edge of the door, wherefore it will differ from BoardingHeight when there are outer steps below the door.
• Quay has PlatformHeight which describes the height of the platform measured from the ground (road vehicles) or top of the rail (rail vehicles).

The vertical gap between vehicle entrance and platform can be calculated using BoardingHeight and PlatformHeight. However as the BoardingHeight represents the lowest entry point before any steps, a vertical gap of ±0 does not guarantee level access. Also one cannot calculate the height difference from the platform to the vehicle's final floor height which is relevant for the usage of a ramp.

Side note: railML also defines two different heights for entrances (see rail:ePassenger/doors)

• entranceHeight: height of entrance foot plate above rail top
• footStepHeight: height of lowest foot step above rail top

NeTEx properties related to the horizontal gap:

• VehicleType and AccessVehicleEquipment already have a property called GapToPlatform which describes an expected gap. However since the gap depends on the platform where the vehicle stops this property is only an estimation.
• VehicleType has a property called Width which divided by 2 gives the distance between the vehicle's center and its outside (only holds true for symmetric vehicles). However this is not necessarily equivalent to the outermost entrance point as vehicles might have other exterior parts that contribute to their width (wing mirrors, curved car body, etc.)
• EquipmentLength is defined as: Length of the EQUIPMENT be it hoist or ramp. When fully extended and only the part outside the VEHICLE. +v2.0
• EdgeToTrackCenterDistance is defined as: Distance between the track centre and the platform edge parallel to the running plane (bq), as defined in chapter 13 of EN 15273-3:2013.

There is no vehicle counterpart to EdgeToTrackCenterDistance to reliably calculate the horizontal gap between vehicle and platform.

Proposal

Add floor height to VehicleType and AccessVehicleEquipment

This aims to define an additional vehicle counterpart (alongside BoardingHeight) to the existing PlatformHeight (defined in PlatformAccessibilitySpecificGroup used on Quays) in order to calculate the height difference between the platform and the vehicle's floor at the entrance. The proposed property name is FloorHeight.

FloorHeight is defined as the height of the immediate inner floor the entrance is connected to. Steps are considered part of the entrance if they must be passed when boarding or alighting the vehicle. When entering a vehicle the measurement point is the first point right after any external or internal steps.

• For road vehicles the height is measured above ground level (AGL). Also see: https://brtguide.itdp.org/branch/master/guide/vehicles/vehicle-floor-height
• For rail vehicle the height is measured above the top of the railhead (ATOR). This is h as defined in EN 15273-1: "Height of a point measured from the running plane"

Difference to BoardingHeight

BoardingHeight describes the height of the outer entry point while FloorHeight is meant to describe the height of the inner entry point. Together they describe the lowest and highest point of an entrance. In most cases FloorHeight will be the highest point but it ultimately depends on the vehicle's design.

───────┬───┐ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ┬
       │   │                     │
       │   └───┐ ─ ─ ┬           │
 Floor │ Step  │     │           │
───────┴───────┤     │           │
               │     │           │ Floor
               │     │ Boarding  │ Height
               │     │ Height    │
               │     │           │
          ┌─┐  │     │           │
──────────│ │──┘     │           │
 Track    └─┘─ ─ ─ ─ ┴ ─ ─ ─ ─ ─ ┴

(Example visualisation of the FloorHeight and BoardingHeight for a rail vehicle)

The FloorHeight of a vehicle might change depending on its load. It must be measured with the same load as the BoardingHeight. A definition is given in ERA/GUI/02-2013/INT chapter 2.5.10. : [...] with design mass as defined in EN 15663:2009

VehicleType

<xsd:group name="VehicleAccessibilityRequirementsGroup">
  <xsd:sequence>
    [...]
    <xsd:element name="FloorHeight" type="LengthType" minOccurs="0">
      <xsd:annotation>
        <xsd:documentation>Height of the vehicle floor next to the entrance measured from the ground of the road or top of the rail.</xsd:documentation>
      </xsd:annotation>
    </xsd:element>
  </xsd:sequence>
</xsd:group>

AccessVehicleEquipment

<xsd:group name="AccessVehicleEquipmentBoardingGroup">
  <xsd:sequence>
    [...]
    <xsd:element name="FloorHeight" type="LengthType" minOccurs="0">
      <xsd:annotation>
        <xsd:documentation>Height of the vehicle floor next to the entrance measured from the ground of the road or top of the rail.</xsd:documentation>
      </xsd:annotation>
    </xsd:element>
  </xsd:sequence>
</xsd:group>

Add distance from center to DeckEntrance

This aims to define the vehicle counterpart to the existing EdgeToTrackCenterDistance (defined in PlatformAccessibilitySpecificGroup used on Quays) in order to calculate the horizontal gap between the platform and the vehicle entrance. The proposed property name reuses EdgeToTrackCenterDistance which is later referred to as DeckEntrance.EdgeToTrackCenterDistance. Like Quay.EdgeToTrackCenterDistance it is only applicable to rail vehicles and not road vehicles.

DeckEntrance.EdgeToTrackCenterDistance is defined based on b as defined in EN 15273-1 (also see image H.1): “Semi-width”: distance of a point on a carbody section or on an infrastructure section, measured with respect to the track centre and parallel to the running plane.

The definition is refined to be the distance from the outer edge of the vehicle entrance to the vehicle axis (center line of the vehicle measured between the axles). The outer edge of the vehicle entrance includes any fixed outer steps of the vehicle, but excludes any moving parts or equipment such as sliding steps, folding steps or automatic ramps.

                Platform
                Distance
            ├─────────────────┤

            |   Entrance      |
                Distance
            ├──────────────┤  |

            |              |  ┌──────────
┌───────────────────────┬──┐  │ Platform
│           |           ├──┘  │
│                       │     │
│  ┌─┐      |      ┌─┐  │     │
└──│ │─────────────│ │──┘     │
   └─┘    Track    └─┘        └──────────

(Example visualisation of the Quay.EdgeToTrackCenterDistance and DeckEntrance.EdgeToTrackCenterDistance for a rail vehicle)

The horizontal gap for straight tracks can then be calculated the following way:

HorizontalPlatformGap = Quay.EdgeToTrackCenterDistance - DeckEntrance.EdgeToTrackCenterDistance

Any equipment that is supposed to bridge the horizontal gap (e.g. a sliding step) can be factored in the following way:

HorizontalPlatformGap = Quay.EdgeToTrackCenterDistance - DeckEntrance.EdgeToTrackCenterDistance - EquipmentLength

(negative results have to be truncated to 0)

DeckEntrance

<xsd:group name="DeckEntrancePositionGroup">
  <xsd:sequence>
    [...]
    <xsd:element name="EdgeToTrackCenterDistance" type="LengthType" minOccurs="0">
      <xsd:annotation>
        <xsd:documentation>Distance from the outer edge of the vehicle entrance (including any fixed outer steps) to the vehicle center (center point between axles).</xsd:documentation>
      </xsd:annotation>
    </xsd:element>
  </xsd:sequence>
</xsd:group>

The addition of this property to AccessVehicleEquipment is up for discussion.

Discarded ideas

Add ground floor height to DeckSpace

Add the floor height to individual DeckSpaces naming the property HeightFromGround as already defined in DeckEntrancePositionGroup. Rationale: Currently this is not required as steps or height differences inside a vehicle can still be modeled via stairs. In the future it may still be useful as a general z-Axis.