Modeling construction elements

The following network objects serve as construction elements for walkable ground:

• Areas
• Ramps & stairs, inlcuding escalators and moving walkways

Obstacles are construction elements that are not accessible.

Moreover, you can designate links as walkable pedestrian areas, thereby modeling the interaction between vehicles and pedestrians. On pedestrian links, you can position signal heads, detectors, priority rules or conflict areas for pedestrians (Modeling links as pedestrian areas).

Note: Add pedestrian inputs to pedestrian areas as a source of pedestrian flows (Modeling pedestrian inputs). Whereas links created with the Is pedestrian area attributes are accessible elements on which you can place signal heads, detectors or conflict areas. They are meant for modeling the interaction of pedestrians with vehicular traffic or other pedestrian flows (Modeling links as pedestrian areas).

Using areas, ramps and stairs

An area is defined as circle, rectangle or polygon (Defining construction elements as circles), (Defining construction elements as rectangles), (Defining construction elements as polygons). Areas do not have a specific direction. You can import areas from AutoCAD.

Ramps and stairways are defined as rectangles. You can choose from various stairway shapes. The shape defines the number and direction of flights and the number of landings. The shape is displayed inside the rectangle.

Ramp can therefore be the generic term for construction elements, which connect areas of different levels: ramps, stairways, escalators, moving walkways.

A stairway must start at one level (top) and end at another level (bottom).

Surfaces and ramps can optionally include other objects that influence pedestrians, such as routing decisions (Modeling pedestrian routing decisions, pedestrian routes and partial pedestrian routes).

You can specify the designation of an area in public transport for pedestrians at stops, classifying it as a waiting area or platform edge, and as a waiting area for pedestrians awaiting an elevator (Modeling PT stops), (Attributes of areas).

Note: Refrain from designating an area for public transport use as both a waiting area or platform edge and a waiting area for pedestrians awaiting an elevator. Instead, define multiple areas, each designated for a specific use type.

Pedestrians utilize walkable ground formed by overlapping construction elements.

Vissim automatically creates connections between accessible construction elements, both among themselves and with pedestrian routes, at the points where they directly touch or overlap. Where the accessible elements overlap, pedestrians may walk from one element into the next one. Pedestrians do not require any connectors between construction elements. If construction elements overlap, it is taken into account whether different walking behaviors are effective (Modeling area-based walking behavior).

Before information on walkable areas is transferred to the pedestrian model, Vissim groups areas touching or overlapping each other into the largest possible walkable polygons. The original edges of these areas are not treated as obstacles. They are pedestrian accessible. To model a complex area containing numerous corners, define several polygons in a row that overlap. By combining all areas and pedestrian routes on one level, Vissim creates the walkable ground of this level. All explicitly defined obstacles are subtracted from this, as well as the following implicit, invisible obstacles:

• Obstacles at the foot and end of a ramp that prevent pedestrians from stepping onto the ramp from the side
• Socket and ceiling opening of a ramp
• Elevator shafts
• Obstacles of 3D signal systems, if their attribute Mast is regarded as pedestrian obstacle is selected

Ramps are not considered part of the walkable ground of a level, even if their start level and end level are identical.

Partitions of non-contiguous, walkable ground

The walkable ground is considered contiguous if it is possible to reach any point from any other point on the walkable ground without the need to cross its edges, traverse a ramp, or utilize an elevator. If the walkable ground of a level is not contiguous, it consists of several contiguous regions. These regions are referred to as partitions.

Stairway shapes

For each stairway you can select the following shapes (Attributes of ramps and stairs, moving walkways and escalators):

• Straight
• Straight with landing
• Angle with quarter landing (90°)
• U with half landing (180°)
• U with 2 quarter landings (180°)

The wireframe shows the following stairway elements:

• The contour includes the length and width of the stairway as an enclosing rectangle. The contour thus covers all flights of stairs including the steps and landings, if the stairway has more than one or two landings.
• Parallel lines over the width of each flight of stairs mark the area of the steps.
• A triangle indicates the direction.

If the stairway has several flights of stairs, you can specify the length and width of each flight of stairs using the Length Flight of Stairs<No> and Width Flight of Stairs <No> attributes.

Using escalators and moving walkways

Pedestrians may use escalators and moving sidewalks for automated transport. Escalators and moving walkways have a direction and are defined as rectangles.

Using obstacles

Obstacles are not accessible. An obstacle has the same effect on pedestrian dynamics as if you were to model a hole in an otherwise accessible area. Obstacles are defined as circles, rectangles or polygons. You can import obstacles from AutoCAD (Importing walkable areas and obstacles from AutoCAD).

If an obstacle intersect a ramp, a message is displayed when you start the simulation. The message shows the number of the obstacle, starting with the smallest number, that intersects a ramp and the number of the ramp. Click the Continue button to show the next message. Click the Cancel button to cancel the start of the simulation, e.g. in order to edit an obstacle.

Deleting construction elements

By default, you may delete construction elements in lists or network editors (Deleting network objects).