Multi-Level Mapping

Introduction

This reference guide, based on ISSprOM 2019-2 Revision 6 (January 2024), provides instructions and examples for multi-level mapping.

512.1 Bridge or Tunnel Entrance

Purpose:

• To indicate a simple bridge or tunnel entrance where it is possible to pass underneath.

Usage Guidelines:

• Passable Underneath: Use this symbol when a bridge or tunnel entrance allows competitors to pass underneath.
• Not Passable: If a bridge cannot be passed underneath, use the symbol for an Uncrossable Wall (515).

Drawing Specifications:

• Cartographic Gap: Leave a 0.15 mm gap between any black objects pointing towards the peaks of the triangles.
• Minimum Representation:
• Use one triangle in complex situations (where multiple features are close together and the area is dense or cluttered). (best avoided if possible!)
• Use two triangles in a standalone situation (when the bridge or tunnel is isolated and not surrounded by other features).
• Sharp Angles: Pay special attention to drawing sharp angles to ensure clarity. Use the correct vertex types for corners.

Example:

• Scenario: A small park bridge spans over a narrow stream, and competitors can run underneath it.
• Mapping: The map shows two black triangles pointing towards the bridge, with a 0.15 mm gap between the triangle peaks and the adjacent black lines, indicating the passable space beneath the bridge.

512.2 Underpass or Tunnel

Purpose:

• To indicate an underpass or tunnel where competitors pass underneath the ground or a structure.

Usage Guidelines:

• Use the Line When:
• There is no other barrier line defining the extent of the lower-level area.
• The underpass or tunnel is long enough to be clearly represented.
• Short Underpasses or Tunnels:
• If the underpass or tunnel is too short for the line to fit (minimum length is two dashes), you can omit the line if the area is also delimited by the "Area Runnable at Lower Level" symbol (512.3).
• Other Barrier Lines: When the upper level is shown on the map for navigational purposes but not used as a running level (e.g., a railway over a main road), the following symbols may define the extent of the lower-level area:
• Uncrossable Wall (515)
• Uncrossable Body of Water (301)
• Area That Shall Not Be Entered (520)
• Building (521)
• Temporary Construction or Closed Area (714)

Drawing Specifications:

• Cartographic Gap: Leave a 0.2 mm gap at the beginning and end of the line.
• Minimum Line Length: The line should be at least 2 dashes long (0.7 mm each, footprint 2.8 m).

Example:

• Scenario: An urban pedestrian tunnel runs underneath a busy road.
• Mapping: The tunnel is represented with a dashed line, with each dash being 0.7 mm long. The line begins and ends with a 0.2 mm gap, clearly indicating the entrance and exit of the tunnel.

512.3 Area Runnable at Lower Level

Purpose:

• To indicate the upper part of a two-level structure where passage is possible at both levels.

Usage Guidelines:

• Use This Symbol For:
• Structures allowing passage at both levels.
• Important Note: The ISSprOM 2019-2 Revision 6 specifies that the "Area Runnable at Lower Level" symbol (512.3) should not be used in combination with symbols like Uncrossable Body of Water (301), Area That Shall Not Be Entered (520), and Building (521). However, the spec also includes mapping examples where these symbols are combined with 512.3. Therefore, it is assumed that such combinations are permitted in practice despite the general guideline. Hopefully, this will be addressed more clearly in the next version.

Combining Symbols and Replacements:

• Shallow Body of Water (302): Replace with Uncrossable Body of Water (301) within the striped area.
• Open Land (401): Remains unchanged.
• Open Land with Scattered Trees (402): Replace with Open Land (401) within the striped area.
• Rough Open Land (403): Replace with Open Land (401) within the striped area.
• Rough Open Land with Scattered Trees (404): Replace with Open Land (401) within the striped area.
• Vegetation: Slow Running (406): Replace with Vegetation: Walk (408) within the striped area.
• Vegetation: Walk (408): Remains unchanged.
• Vegetation: Fight (410): Remains unchanged.
• Uncrossable Vegetation (411): Remains unchanged.
• Cultivated Land (412): Replace with Open Land (401) within the striped area.
• Orchard (413) and Vineyard or Similar (414): Replace with Open Land (401) within the striped area.
• Paved Area (501): Use brown 50% (heavy traffic brown) to improve contrast against the white stripes.
• Paved Area with Scattered Trees (501.3): Replace with Paved Area (501) within the striped area.
• Area That Shall Not Be Entered (520): Remains unchanged.
• Building (521): Remains unchanged.
• Canopy (522): Remains unchanged.
• Out-of-Bounds Area (709): Replace with 100% purple colour within the striped area.
• Temporary Construction or Closed Area (714): Replace with 100% purple colour within the striped area.

Drawing Specifications:

• Angle of Pattern: The pattern should be drawn at an angle of approximately 45° to the direction of the area it describes.
• Surface Representation: Adjust the symbol combination depending on the surface on the upper level to ensure accurate representation of the terrain.

Example:

• Scenario: An elevated walkway crosses over a street, with space for pedestrians to pass underneath.
• Mapping: The upper level of the walkway is shown with a striped pattern angled at 45°, combined with the "Paved Area" symbol to represent the walkway's surface. The lower level is clearly runnable, indicated by the appropriate symbols for the terrain.

501.2 Step or Edge of Paved Area at Lower Level

Purpose:

• To indicate the step or edge of a paved area at a lower level if it is useful for navigation.

Usage Guidelines:

• Use This Symbol For:
• Large areas with two levels where the step or edge needs to be marked for navigation purposes.
• Important Note: This symbol should only be used when it is necessary for navigation.

Drawing Specifications:

• Cartographic Gap: Leave a 0.15 mm gap at both ends of the line to ensure clarity.
• Colour: Black.

Example:

• Scenario: A large paved area with a service road running underneath at a lower level.
• Mapping: The step or edge of the paved area is shown with a black line, representing the shape of the road underneath. The line includes a 0.15 mm gap at both ends to clearly indicate the transition between the levels.

522 Canopy

• Canopy Symbol: The Canopy symbol (522) may be more appropriate than 512.2 if there is only one running level and there is no navigational detail within the area covered by the canopy.

Quick Reference Summary:

• 512.1 Bridge or Tunnel Entrance: For bridges or tunnels passable underneath; use two triangles in a standalone situation (when the bridge or tunnel is isolated and not surrounded by other features) but one triangle is permitted in a complex situation (when the bridge or tunnel is in a dense or cluttered environment).
• Example: Park bridge over a stream.
• 512.2 Underpass or Tunnel: For passages under ground or structures; use a dashed line with proper gaps unless very short, in which case omit if delimited by "Area Runnable at Lower Level." When the upper level is used for navigation but not as a running level, define the lower-level area with other symbols such as Uncrossable Wall (515) or Uncrossable Body of Water (301).
• Example: Pedestrian tunnel under a road.
• 512.3 Area Runnable at Lower Level: For areas where passage is possible at multiple levels; combine with relevant symbols for accurate terrain representation.
• Example: Elevated walkway over a street.

FAQ’s