Modeling construction elements

The following network objects are accessible construction elements:

• Areas
• Ramps, stairways, escalators, moving walkways

Obstacles are not accessible

Areas, Ramps & 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 select different 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).

Areas and ramps may optionally include additional information for pedestrians, e.g. routing decisions (Modeling routing decisions and routes for pedestrians).

You can define public transport stop areas as waiting areas or platform edges (Modeling PT stops), (Attributes of areas).

Construction elements are automatically connected where they are directly adjacent or overlap. Where accessible elements overlap, pedestrians may walk from one element into the next one. Pedestrians do not require any connectors. 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. So when you split an area during network editing, this does not affect pedestrian simulation in the network.

To model a complex area containing numerous corners, define several polygons in a row that overlap.

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).

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.

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.

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).